SMART START!

1. What units of measurement would you use to measure the distance between Arlington and Dallas, TX?

2. What units would you use to tell someone the temperature: Celsius or Fahrenheit?

3. Can you think of a unit that would allow you to accurately measure the width of a human hair: mm, cm, or km?

4. Do you think other countries measure distance, time, temperature, etc. the same as the United States? Why or why not?

I need 2 volunteers…

• I need two scholars to come to the front of the room for a short demonstration.

• It is your job to measure the distance from one wall to the other using the ruler in centimeters and report it back to the class when you are finished.

What are SI Units?

• Scientists, and most of the world, use the International System of Measurement – SI Units. {Also known as the metric system.

• SI Units are a worldwide system of measurements that scientists have agreed to use in their work.

• This means that scientists all over the world in every country and in every language, use the SI system of measurement!

• The United States is one of the only countries who does not use the metric system as their standard measurements.

• Each type of measurement in SI has a base unit.

• Such as meter for length/distance or seconds for time.

• Let’s take a look at the most common base units we will use in this class and what they measure.

Base Units

• Length is the measurement of how long something is. Distance is the measurement of how far something is.

• When scientists want to measure the length or the distance of something, they’re going to use the base unit, meter.

• The symbol for the meter is (m). – Lowercase for base units!

Length/Distance

• Mass is the amount of matter in an object. – It is not the same as weight!

• When scientists measure mass, they use grams.

• The symbol for the gram is (g).

Mass

• Volume is the amount of space an object takes up.

• When scientists measure volume, they use liters.

• The symbol for liters is (L). – The only base unit whose

symbol is uppercase!

Volume

• Temperature is a measure of the average kinetic energy of particles.

• When scientists measure temperature, they use degrees Celsius.

• The symbol for the Celsius is (°C).

Temperature

• We can think of time as the duration of an action or specific events of the past, present, and future.

• When scientists measure time, they use seconds.

• The symbol for the seconds is (s).

Time

Why do scientists think that using the metric system is easier than other systems of

measurement?

Think-Pair-Share

SI Prefixes

• A prefix is a letter or word that’s placed in front of another word to give it meaning.

• In SI Units, prefixes are added to base units to create larger and smaller units for that quantity.

• To indicate measurements much larger or much smaller than the base unit, you add a prefix to the base unit label.– For example, adding milli- to liter is a milliliter. – Adding kilo- to meter makes a kilometer.

• SI Units are all powers of 10, that means that all prefixes indicate units that are 10 times larger, or smaller than the unit on either side of it. – Milli- always means 1/1000 of a base unit. That means that a milligram

is 1/1000th (fraction) the size of a gram. – Kilo- always means 1000 times the size of the base unit. That means

that a kilogram is 1000 times larger (multiple) of a gram.

Adding a Prefix to a Base Unit

• There are way more prefixes than you will ever need to use in your life.

• However, there are six common prefixes that you do need to know.

• We can look at these prefixes in the form of a ladder.

Adding a Prefix to a Base Unit

SI PrefixesPrefix Ladder

Kilo –1,000

k Deka–10

dk or da

Hecto–100

h Base Unit1

Liter (L)Meter (m)Gram (g)

Deci –1/10

dCenti –1/100

cMilli –1/1000

m

Using the symbols for prefixes AND base units, what would the symbol be for a centigram?

Conceptual Demonstration

Prefix Ladder

Kilo –1,000

k Deka–10

dk or da

Hecto–100

hBase Unit

1Liter (L)

Meter (m)Gram (g)

Deci –1/10

dCenti –1/100

cMilli –1/1000

mConvert 203 hectograms to their base unit.

Each indicates that you are multiplying by 10 since you are going down the ladder.203 hectograms 2030 dekagrams 20,300 grams

Prefix Ladder

Kilo –1,000

k Deka–10

dk or da

Hecto–100

hBase Unit

1Liter (L)

Meter (m)Gram (g)

Deci –1/10

dCenti –1/100

cMilli –1/1000

m250 millimeters to kilometers250mm ÷ 10 = 25cm25cm ÷ 10 = 2.5 decimeters2.5dm ÷ 10 = .25 m.25m ÷ 10 = .025 dekameters.025 ÷ 10 = .0025 hm.0025 ÷ 10 = .00025km

Prefix Ladder

Kilo –1,000

k Deka–10

dk or da

Hecto–100

hBase Unit

1Liter (L)

Meter (m)Gram (g)

Deci –1/10

dCenti –1/100

cMilli –1/1000

m1600mm to dekameters

Prefix Ladder

Kilo –1,000

k Deka–10

dk or da

Hecto–100

hBase Unit

1Liter (L)

Meter (m)Gram (g)

Deci –1/10

dCenti –1/100

cMilli –1/1000

m1600mm to dekameters

Prefix Ladder

Kilo –1,000

k Deka–10

dk or da

Hecto–100

hBase Unit

1Liter (L)

Meter (m)Gram (g)

Deci –1/10

dCenti –1/100

cMilli –1/1000

m19.045cl to kiloliters

• Think about King Henry…

http://www.brainpop.com//science/scientificinquiry/metricunits/

How do we remember these prefixes!?

King Henry Doesn’t Usually Drink Chocolate Milk

How do we remember these prefixes!?

Lastly…

• DON’T FORGET TO LABEL YOUR UNITS!• 5 doesn’t tell you anything… – It could mean…

Numbered Heads/Jigsaw

• Everyone in your table group will need to number off from 1-4 (it’s okay if there are duplicate numbers in a table group. • All the number 1’s will work on box 1 of the guided notes.• All the number 2’s will work on box 2 of the guided notes.• All the number 3’s will work on box 3 of the guided notes• All the number 4’s will work on box 4 of the guided notes.

18 min

Numbered Heads/Jigsaw

• Your job is to identify the best unit for each example measurement. • You must choose the correct base unit and prefix. • Some of them might just be the base unit with no prefix!

18 min

Numbered Heads/Jigsaw

• After 3 minutes, scholars will get together with other 1’s, 2’s, 3’s, and 4’s from other table groups to compare and discuss answers. • When you have agreed on the correct units, you will take your information back to your table group and share for 5 minutes.

18 min

Numbered Heads/Jigsaw

• Silently begin working on your assigned questions. Don’t forget to explain why.• Do not work ahead on any other questions in other boxes. • You will have 3 minutes to complete your questions. • If you need any references of quantities, use the information sheet at each table or the materials at the front of the room.

3 min

Numbered Heads/Jigsaw

• All of the 1’s meet in the front right corner of the room.• All the 2’s meet in the back right corner of the room.• All of the 3’s meet in the front left corner of the room. • All of the 4’s meet in the back left corner of the room.• Discuss your units and come up with a consensus about what units to use to measure the quantities.

4 min

Numbered Heads/Jigsaw

• All scholars should go back to their table group. • Each scholar will share out for about a minute about the quantities in their box while their group members take notes. • By the end, all scholars should have every question filled in. • Voice level 1• 5 minutes

5 min

Independent Practice

• Silently work on the worksheet over SI Units.

• Fill in the blank boxes (quantity, unit, symbol) of the top section based on the information already provided to you.

• Explain the meaning of the prefixes in the bottom table –

• Ex. Kilo- is 1000 times larger than the base unit.

• Fill in the blanks at the very bottom of the page.

• If you finish early, ask your teacher for extension activity materials.

20 min

Complete the exit ticket silently and stack at your table group when you are finished.

You may pack up your things.

Exit Ticket 5 min

STOP CardsS Summarize: Summarize the day’s lesson and what we learned.T Trait: What IB trait relates to the lesson?O Objective: Re-state in your own words and say whether or not we met that objective for the day.P Purpose: What was the purpose of this lesson?