GRADE 5 • UNIT 2 Table of Contents

Multi-Digit Whole Number and Decimal Fraction Operations

Lessons

Topic 1: Mental Strategies for Multi-Digit Whole Number Multiplication 1-2 Lesson 1: Multiply multi-digit whole numbers and multiples of 10 using place value patterns and the distributive and associative properties.

Lesson 2: Estimate multi-digit products by rounding factors to a basic fact and using place value patterns.

Topic 2: The Standard Algorithm for Multi-Digit Whole Number Multiplication 3-9 Lesson 3: Write and interpret numerical expressions and compare expressions using a visual model.

Lesson 4: Convert numerical expressions into unit form as a mental strategy for multi-digit multiplication.

Lesson 5: Connect visual models and the distributive property to partial products of the standard algorithm without renaming.

Lessons 6 & 7: Connect area diagrams and the distributive property to partial products of the standard algorithm without renaming.

Lesson 8: Fluently multiply multi-digit whole numbers using the standard algorithm and using estimation to check for reasonableness of the product.

Lesson 9: Fluently multiply multi-digit whole numbers using the standard algorithm to solve multi- step word problems.

Topic 3: Decimal Multi-Digit Multiplication 10-12 Lesson 10: Multiply decimal fractions with tenths by multi-digit whole numbers using place value understanding to record partial products.

Lesson 11: Multiply decimal fractions by multi-digit whole numbers through conversion to a whole number problem and reasoning about the placement of the decimal.

Lesson 12: Reason about the product of a whole number and a decimal with hundredths using place value understanding and estimation.

Topic 4: Measurement Word Problems with Whole Number and Decimal Multiplication 13-15

Lesson 13: Use whole number multiplication to express equivalent measurements.

Lesson 14: Use decimal multiplication to express equivalent measurements.

Lesson 15: Solve two-step word problems involving measurement and multi- digit multiplication.

Topic 5: Mental Strategies for Multi-Digit Whole Number Division 16-18 Lesson 16: Use divide by 10 patterns for multi-digit whole number division.

Lessons 17–18: Use basic facts to approximate quotients with two-digit divisors.

Topic 6: Partial Quotients and Multi-Digit Whole Number Division 19-23 Lesson 19: Divide two- and three-digit dividends by multiples of 10 with single-digit quotients and make connections to a written method.

Lesson 20: Divide two- and three-digit dividends with single-digit quotients and make connections to a written method.

Lesson 21: Divide two- and three-digit dividends by two-digit divisors with single-digit quotients and make connections to a written method.

Lessons 22–23: Divide three- and four-digit dividends by two-digit divisors resulting in two- and three-digit quotients, reasoning about the decomposition of successive remainders in each place value.

Topic 7: Partial Quotients and Decimal Multi-Digit Division 24-27 Lesson 24: Divide decimal dividends by multiples of 10, reasoning about the placement of the decimal point and making connections to a written method.

Lesson 25: Use basic facts to approximate decimal quotients with two-digit divisors, reasoning about the placement of the decimal point.

Lessons 26–27: Divide decimal dividends by two-digit divisors, estimating quotients, reasoning about the placement of the decimal point, and making connections to a written method.

Topic 8: Measurement Word Problems with Multi-Digit Division 28-29 Lessons 28–29: Solve division word problems involving multi-digit division with group size unknown and the number of groups unknown.

Vocabulary

Familiar Terms and Symbols1

≈ - “is about”, used for estimation of numbers

Decimal - a fraction whose denominator is a power of ten and whose numerator is expressed by figures placed to the right of a decimal point

Digit - a numeral between 0 and 9

Dividend - the number that is to be divided

(e.g., 250 ÷ 5 = 50, 250 is the dividend and goes inside the division house 5)250 )

Divisor - the number by which another number is divided

(e.g., 250 ÷ 5 = 50, 5 is the divisor and goes outside the division house 5)250 )

Equation - a statement that the values of two mathematical expressions are equal, has an equal sign =

Equivalence - a state of being equal or equivalent

Equivalent measures (e.g., 12 inches = 1 foot; 16 ounces = 1 pound)

Estimate - approximation of the value of a quantity or number, you will see the word “about”

Exponent - the number of times a number is to be used as a factor in a multiplication expression

e.g. 102 = 10 x 10 = 100 the two is the exponent

Factor - the numbers being multiplied (e.g., 3 x 4 = 12, 3 and 4 are factors)

Multiple - a number that can be divided by another number without a remainder like 15, 20, or any multiple of 5

Partial product – a method of multiplying in which each digit is multiplied separately; the answers are the partial products. They are then added together to get the final result/answer/product.

Example: 3,201.4 x 2 = (3,000 x 2) + (200 x 2) + (1 x 2) + (0.4 x 2) = 6,000 + 400 + 2 + 0.8 = 6,402.8

Partial quotient – a method of dividing in which multiples of the divisor are subtracted from the dividend and then the quotients are added together.

Example: to see how this is done you can watch the video found at the link below:

http://everydaymath.uchicago.edu/teaching-topics/computation/div-part-quot/

Pattern - a consistent and recurring trait within a sequence

Product – the answer or total when two numbers (factors) are multiplied

Quotient – the answer when dividing one number (dividend) by another (divisor)

Remainder - the number left over when one integer is divided by another

Renaming - making a larger unit that is equivalent

Rounding - approximating the value of a given number Unit Form - place value counting, (e.g., 34 stated as 3 tens 4 ones)

Number bond

1 These are terms and symbols students have used or seen previously.

10

8 2 Number Bond

New Vocabulary for 5th Grade Unit 2

Decimal Fraction - a proper fraction whose denominator is a power of 10 (ex 0.3 = 3/10)

Decompose – to break apart into smaller pieces or parts (ex 321 = 300 + 20 + 1)

Multiplier - a quantity by which a given number—a multiplicand—is to be multiplied ie factor

Order of Operations – Parentheses, Exponents, Multiplication & Division, Addition & Subtraction

Parentheses - the symbols used to relate order of operations ( )

Lesson by Lesson Suggestions Lesson 3: Writing Simple Expressions Parent Tip: Writing expressions can be extremely hard for students since there are so many things to consider at the same time. Remind your children to slow down and think about each step, one at a time, to prevent them from becoming frustrated.

7 multiplied by the sum of 4 and 2

Think carefully about what you must include, and the order in which you should write it. Make a list of the things you know you must include:

o The numbers 7, 4, and 2. o "multiplied" tells me I will need the operation of multiplication. o "sum" tells me that I will need the operation of addition, “difference” would mean to subtract o "Multiplied by the sum" tells me that I will need to get the sum of 4 and 2 before multiplying.

Based on the correct order of operations shown above addition comes after multiplication, I will need to put 4 + 2 inside parentheses to

“seven multiplied by the sum of four and two” = 7 x (4 + 2)

4 + 2 is in parentheses to make sure this addition is done first. Without the parentheses, the operation of multiplication would have to be done first, based on the order of operation rules.

Another way you could write it is just: 7(4 + 2) A number right next to a parentheses mark, with no operation sign in between, means to multiply.

Note: Parentheses are not needed to show multiplication or division happening first, because the rules for the order of operation already say that they come before any adding or subtracting.

EX) Three times the difference between eighteen and thirteen 3 x (18 - 13)

Ex) Five less than the product of eight and three 8 x 3 – 5 or (8 x 3) -5

Models to show expressions

Representing Multiplication & Division Using Models

Students are expected to demonstrate an understanding of mathematical operations (add, subtract, multiply & divide) using models*, explanations**, and/or solving real world word problems***.

*Common models to show mathematical concepts are: set models, arrays, area models, and number lines. (Examples of each type of model will be provided.) ** Explanations refer to a verbal or written description of how the operation works or how the problem was solved. Students must use words and complete sentence to state their answer. ***Solving problems means coming up with an answer to a problem situation using any method. The problem may be solved using words, numbers, or pictures (models).

Multiplication

Ex) The party had 23 tables. Each table had 18 chairs. How many chairs were there altogether? Students in lower grades, seeing the problem above, may draw 23 tables with 18 chairs at each table and then count how many chairs. This would be an example of the set model and would be a cumbersome project. In Grades 4 and 5, students should know that this is a situation that calls for multiplication and the model needs to be more suited to showing large numbers.

Numerical Ways to Multiply 2 digit by 2 digit

Here are a few examples of numerical ways that students could find 23 x 18 without using the standard algorithm:

Find a smaller product (23 x 6) and triple the result; because 18 is made with 6 x 3

23 x 6 = (20 x 6) + (3 x 6) = 120 + 18 = 138 138 x 3 = (100 x 3) + (30x3) + (8x3) = 300 + 90 + 24 = 414

Look for landmark numbers, numbers that are easier to work with using mental math (this will be taught and practiced in Lesson 4)

23 x 18 is close to 25 x 18. 25 is easier to multiply with a landmark number. If we can find 25 x 18 and take away 2 x 18, we will have 23 x 18.

Since 25 x 4 = 100, then 25 x 16 = 400 and 25 x 2 = 50 so 25 x 18 = 450 We need to subtract off 2 x 18. (which is 36) 450 – 36 = 414

Lesson 4: A Mental Strategy for Multiplying Numbers

Example 1: 25 x 12 “Should we use twenty-fives as the unit or twelves as the unit?”

12 is 2 away from 10, 25 is 5 away from 20 so we will use 12 twenty-fives. It makes more sense to use 25 as the unit because 12 is closer to a whole ten.

We can think about 12 twenty-fives as 10 twenty-fives + 2 twenty-fives.

Draw a tape diagram: Show 10 twenty-fives, then add on 2 more.

25 25 25 . . . (symbolizes the continuation 25 25 25

of a pattern)

10 twenty-fives 2 twenty-fives

Think: 10 twenty-fives + 2 twenty-fives = (10 x 25) + (2 x 25) = 250 + 50 = 300

Example 2: 18 x 17 “Should we use eighteens as the unit or seventeens as the unit?”

18 is 2 away from 20, 17 is 3 away from 20 so we will use 18 seventeens It makes more sense to use 17 as the unit because 18 is closer to a whole

ten.

We can think about 18 seventeens as 20 seventeens - 2 seventeens. Draw a tape diagram: Show 20 seventeens, then subtract 2 seventeens.

20 seventeens

17 17 17 . . . 17 17 17

18 seventeens

Think: 20 seventeens - 2 seventeens = (20 x 17) - (2 x 17) = 340 - 34 = 306

**We know that this may seem like more work and more steps and a round about way to multiply – remember the goal of this lesson is to teach a deeper understanding of number operations – not

just get the right answer.**

Models to Show Multiplication: 1-digit by 1-digit Multiplication Array model for 4 x 3

2-digit by 1-digit Multiplication

Array model for 12 x 3 using only unit cubes: Note that the above array model could also be expressed as two arrays (10 x 3) and (2 x 3)

10 2

By breaking the 12 up into 10 + 2, the product 36 is easier to visualize and easier to build using the Base Ten Blocks. This breaking up of numbers will later be called decomposing.

Area models – a more abstract version of an array that does not show each individual unit

Multiplication using an area model is presented starting in grade 3 using arrays and then through grade 5 for multiplication for larger numbers.

7 x 5 24 x 6

248 x 9

4

12 square units

12

3

36 square units

3 3

30 square units

6 square units

3

7

5 35

20 4

6 120

24 x 6 = 120 + 24 = 144 7 x 5 = 35

24

9

200 40 8

1800 360 72

248 x 9 = 1800 + 360 + 72 = 2,232

2-digit by 2-digit Multiplication When representing a 2-digit by 2-digit product using the array model, the same idea of decomposing numbers into units of 1’s and 10’s is used to make the total number of square units in the arrays easier to visualize.

For example: 23 x 18

To model this we need an array that is 23 units on one side and 18 units on the adjacent side.

- We can decompose 23 to make 20 + 3 - We can decompose 18 to make 10 + 8

By doing this, four rectangles are formed. We can use mental math to calculate the areas.

To find 23 x 18, we can add the areas of the four arrays, the separate products are called the partial products. The partial products are added to get the final product.

23 x 18 = (20 x 10) + (3 x 10) + (20 x 8) + (3 x 8) = 200 + 160 + 30 + 24 (partial products) = 414

Lessons 5-9: Multi-Digit Whole Number Multiplication Area Model & Standard Algorithm The concrete models of multiplication shown on the previous pages limit the size of numbers students can use. In 5th grade, students will be solving 3-digit by 3-digit multiplication and beyond. The concrete model using base ten blocks or using graph paper visualizing the actual numbers becomes cumbersome. After experience with the concrete, the students need to move into a more abstract area model. Students will still show the rectangles formed by multiplication, but they do not have to use models having an exact scale/size. They do not have to be exactly to scale, though if one dimension is less than another, it should be shown in the picture. Students will also learn to use the standard algorithm at the same time.

Example 1: 89 x 47

Example 2: 167 x 23

Example 3: 253 x 174 = 20000 + 14000 + 800 + 5000 + 3500 + 200 + 300 + 210 + 12

= 44,022

50 3

70

4

200

100

3

40

20 2000

000

1200 140 Standard Algorithm:

167

x 23

501

+3340

3,841

47 x 89 = 3200 + 360 + 560 + 63 = 4,183

80 9

7

40 x 80 = 3200

7 x 80 = 560

40 x 9

=360

7 x 9 = 63

100 60 7

300 180 2

1

= 2000 + 1200 + 140 + 300 + 180 + 21

= 3,841

20000 5000 300

14000 3500 210

800 200 12

Standard Algorithm:

89

x 47

623

+3560

4,183

Standard Algorithm:

253

x 174

1012

17710

+ 25300

44022

Lessons 10-12: Multiplication of Decimals Using the Area Model & Standard Algorithm The decimal multiplication in this and following lessons builds on the concept of whole number multiplication in earlier unit lessons and the single - digit decimal multiplication from Unit 1. It is important for students to note that because multiplication is commutative, multiplication sentences may be written in any order. In this part of the unit, the decimal factor will be designated as the unit (multiplicand—the what that is being multiplied) while the whole number will be treated as the multiplier (the how many copies number). This interpretation allows students to build on the repeated addition concept of multiplying whole numbers, which has formed the basis of the area model as students understand it. This makes the distributive property and the partial products of the algorithm a direct parallel to whole number work.

Example 1: 43 x 2.4 Another way to think about this problem:

The student demonstrates this with the algorithm by multiplying by 10 and then dividing by 10. It’s like multiplying by 1!

Example 2: 7.38 x 41

40

43 x 24 tenths = 800 + 160 + 60 + 12

= 1,032 tenths = 103.2

20 4 tenths

3

40 x 20 = 800

3 x 20 = 60

40 x 4 = 160

3 x 4 = 12

Standard Algorithm:

24 tenths

x 43

72

+ 960

1,032 tenths = 103.2

Lessons 13-15: Measurement Word Problems with Whole Number and Decimal Multiplication Students explore multiplication as a method for expressing equivalent measures. For example, they multiply to convert between meters and centimeters or ounces and cups with measurements in both whole number and decimal form. These conversions offer opportunity for students to not only apply their knowledge of multi-digit multiplication of both whole and decimal numbers, but to also reason deeply about the relationships between unit size and quantity—how the choice of one affects the other.

Students will be given and permitted to use a reference sheet as shown below.

Grade 5 Mathematics Reference Sheet

FORMULAS

Right Rectangular Prism Volume = lwh (length x width x height)

Volume = Bh (base x height) CONVERSIONS

1 centimeter (cm) = 10 millimeters (mm)

1 meter (m) = 100 centimeters = 1,000 mm

1 kilometer (km) = 1,000 meters

1 gram (g) = 1,000 milligrams (mg)

1 kilogram (kg) = 1,000 grams

1 pound (lb) = 16 ounces (oz)

1 ton (T) = 2,000 pounds

1 cup (c) = 8 fluid ounces (fl oz)

1 pint (pt) = 2 cups

1 quart (qt) = 2 pints

1 gallon (gal) = 4 quarts

1 liter (L) = 1,000 milliliters (mL)

1 kiloliter (kL) = 1,000 liters (L)

1 mile = 5,280 feet

1 mile = 1,760 yards

The measurements below will not be provided and should already be memorized.

**Time** **Standard Lengths**

1 minute (min) = 60 seconds 1 foot (ft) = 12 inches (in)

1 hour (hr) = 60 minutes 1 yard (yd) = 36 inches

1 day = 24 hours = 3 feet

1 year = 365 days

= 52 weeks

= 12 months

A number line can also be used to show measurement conversions and equivalence.

A few notes on division: There are two distinct interpretations for division. Although the quotients (answers) are the same, the approaches are different.

Partitive Division: 15 apples were placed equally into 3 bags. How many apples were in each bag?

Measurement Division: 15 apples were put in bags with 3 apples in each bag. How many bags were needed?

Lesson 16: Divide by 10 patterns for multi-digit whole number division.

Example 1: 420 ÷ 10

The disk representations used here are a shorthand version of the work done in Unit 1 with place value mats. Some students may need to see the division on the mat using arrows before moving directly to drawn disks.

Example 2: 1,600 ÷ 100

Students will also learn to solve similar problems using their knowledge of place value. The first step is to write the dividend and divisor in unit form.

Example 3: 24,000 ÷ 600

This example has a divisor that is a multiple of 100. Students will decompose 600 with 100 as a factor. (100 x 6 = 600, so 600 ÷ 100 = 6) We can then divide 24,000 by 100, and finally divide 240 by 6.

Lessons 17-18: Using basic facts to estimate quotients

The word whole is used throughout the unit to indicate the dividend – the number being divided. The choice of this term is two-fold. First, whole provides a natural scaffold for the fraction work that is to come in Units 3 and 4. Second, the words dividend and divisor are easily confused. While the word dividend can certainly be included as well, students may find whole to be an easier term.

Example 1: Estimate the Quotient 402 ÷ 19

Students will be asked to identify the whole (402), then identify the divisor (19). Step 1: Round the divisor. For this example we will round the divisor, 19, to the nearest ten which happens to be the greatest place of value found in the number. We will use this symbol (≈) which means “is about”.

19 ≈ 20

Step 2: Round the whole, 402, to a number that can easily be divided by 20.

The estimated quotient is 20. Tip: Having students write the multiples of the 20, 40, 60, 80, 100… or 20 rounded divisor in a vertical or horizontal list as 40 they count can provide a helpful support. 60

80 100

The skill that will help most with estimation and all division moving forward is knowing by memory multiplication facts.

PLEASE PRACTICE AND KNOW YOUR MULTIPLCATION FACTS!!!

Lessons 19 - 23: Partial quotients and multi-digit whole number division The next set of lessons leads students to divide multi-digit dividends by two-digit divisors using the written vertical method (known as the standard long division algorithm). Each lesson moves to a new level of difficulty beginning with divisors that are multiples of 10 (Examples 1 & 2 below) to non-multiples of 10. Two days are devoted to single-digit quotients with and without remainders before moving onto two- and three-digit quotients. Students will use the estimation skills from previous lessons to start and to check the reasonableness of their answers.

Example 1: Example 2:

Example 3: Steps - Round the divisor

- Find a multiple of 20 that will make the division easy and estimate the quotient

- Use the estimated quotient of 3 to start the long division

- Multiply 21 x 3, if the product is less than the whole (72) you can continue *If not reduce the quotient digit by 1*

- Subtract the product of 21 x 3 (63) from 72

- the number left is the remainder as long as it is less that the divisor

Example 4:

The 5th Grade math standards specifically require students to find quotients “using strategies based on place value”. When dividing, students are decomposing units just as they have done when subtracting since Grade 2. “I don’t have enough tens to subtract, so I’ll change 1 hundred for 10 tens.” When dividing, they also change each larger unit that cannot be divided for smaller units. “I’ll change 8 remaining tens for 80 ones.” This language will be used as we extend division to include multi-digit quotients.

Example 5: 590 ÷ 17

In the example above after we use estimation to place the first digit (3) in the quotient, we follow the same steps as before (multiply 17 x 3, subtract 51 from 59, and end up with 8). Since we cannot divide 8 by 17 we rename/regroup the 8 tens as 80 ones and add to it any additional ones from the dividend. In this example there are 0 ones so we use 80 to estimate a second time. This process continues until no further regrouping can be done.

Example 6: 839 ÷ 41

Often times after subtracting and regrouping the number left is less than the divisor. In the example above, 19 cannot be divided by 41, so a 0 is placed in the quotient and the 19 becomes the remainder.

Lessons 24 - 27: Partial quotients and multi-digit decimal division

This topic uses the knowledge students have gained about whole number division with double-digit divisors and extends it to division of decimals by double-digit divisors. Placement of the decimal point in quotients is based on students’ reasoning about when wholes are being shared or grouped, and when the part being shared or grouped transitions into fractional parts. Students will reason about remainders in a deeper way than in previous grades. (Example of this shown in Lesson 26.)

Students will begin again by dividing by multiples of 10. Place value disks and charts will also be used.

Example 1: First shown with place value disks.

54 ÷ 10 5.4 ÷ 10 0.54 ÷ 10

After using place value disks, students will use a place value charts to show division by multiples of 10 (10, 100, 1000). Shown to the right ->

Example 2: When dividing by multiples of 10 we first factor the power of 10 from the divisor.

54 ÷ 90 5.4 ÷ 90 54 ÷ 900 Note: Students must be fluent with their multiplication facts to be successful with these lessons. Example 3: 1.2 ÷ 6 = 0.2 (6 x 2 = 12, 12 ÷ 6 = 2, 1.2 = 12 tenths: 12 tenth ÷ 6 = 2 tenths)

Lesson 25: Students will use basic facts to estimate decimal quotients.

Example 1: 39.1 ÷ 17 3.91 ÷ 17

Lesson 26: Students will divide decimal dividends by two-digit divisors, estimating quotients, reasoning about the placement of the decimal point, and making connections to a written method.

Example 1: 904 ÷ 32 Students will use estimation and regrouping strategies as they complete the standard algorithm.

Students will reason about remainders: This -> example provides an opportunity for students to explore the idea that quotients with whole number remainders of the same digits, are not

necessarily equivalent. Finding decimal quotients is one way to get a more precise comparison.

Lessons 28 - 29: Measurement word problems with multi-digit division Students apply the skills learned in this unit to solve multi-step word problems using multi-digit division. Problems will include unknowns representing either the group size or number of groups. It is important for students to check the reasonableness of their solutions. Students relate calculations to reasoning about division through a variety of strategies including place value, properties of operations, equations, area models, and tape diagrams.

Example 1:

Ava is saving for a new computer that costs $1,218. She has already saved half of the money. Ava earns $14.00 per hour. How many hours must Ava work in order to save the rest of the money? Example 2:

Michael has a collection of 1,404 sports cards. He hopes to sell the collection in packs of 36 cards and make $633.75 when all the packs are sold. If each pack is priced the same, how much should Michael charge per pack?

Example 3: Jim Nasium is building a tree house for his two daughters. He cuts 12 pieces of wood from a board that is 128 inches long. He cuts 5 pieces that measure 15.75 inches each, and 7 pieces evenly cut from what is left. Jim calculates that due to the width of his cutting blade, he will lose a total of 2 inches of wood after making all the cuts. What is the length of each of the seven pieces?

Example 4: A load of bricks is twice as heavy as a load of sticks. The total weight of 4 loads of bricks and 4 loads of sticks is 771 kilograms. What is the total weight of 1 load of bricks and 3 loads of sticks?

Helpful Tips:

- When using a tape diagram that is divided into to more than 10 equal parts,

encourage students to use dot, dot, dot to indicate the uniformity of the equal parts in the tape diagram to save time and space.

- Throughout this unit there must be more emphasis placed on the understanding of what division is, not just the algorithm steps (divide, multiply, subtract, bring down.) Students will develop a better foundation and be more successful with applying these concepts if they understand the skill.

- Keep practicing those multiplication facts – fluency is key! **This site has a video providing guidance for every homework page.**

http://www.oakdale.k12.ca.us/ENY_Hmwk_Intro_Math (Click on 5th Grade – Select the Module to match the unit – Select the lesson)

Recommended Resources Multiplication with Array/Area Models: http://vimeo.com/71591873

Using Graph Paper to Model 2-digit by 2-digit Multiplication The graph paper will need to have fairly small squares in order to accommodate the large numbers that may arise when multiplying 2-digit by 2-digit numbers. An online resource for designing graph paper can be found at: http://www.incompetech.com/beta/plainGraphPaper/

Select “Graph Generator Lite” and enter the following parameters: 8 ½ x 11 (portrait) Grid Line Weight: Fine Square Size: .25 inches Number of Squares: 30 by 40 Grid Color: Black

The illustration shows the area model of multiplying 35 x 26 on graph paper.

Partial Quotients

http://everydaymath.uchicago.edu/teaching-topics/computation/div-part-quot/

Dividing Decimals by Multiples of 10 https://s3.amazonaws.com/ck12bg.ck12.org/curriculum/101874/video.mp4

Dividing Decimals by Multiples of 100 https://s3.amazonaws.com/ck12bg.ck12.org/curriculum/101875/video.mp4

Dividing Decimals by Multiples of 100 https://s3.amazonaws.com/ck12bg.ck12.org/curriculum/101876/video.mp4