Place Value Place Value Through Through

ThousandthsThousandthsLesson 1-3 Lesson 1-3

ACOS N1.2ACOS N1.2

Key IdeaKey Idea

Numbers less than 1 can be written using decimal place value.

Place ValuePlace Value• A decimal is a number with a decimal point (.) . A

decimal point separates the whole numbers from the part that represents part of one whole. As with whole numbers, each digit to the right of the decimal point has its own value. The place-value chart shows the names of the places.

• The decimal 4.853 is made up of 4 ones, 8 tenths, 5 hundredths, and 3 thousandths.

It’s a FACT!It’s a FACT!• Use place value to read a decimal or

to determine the value of a digit in a decimal numeral. In the decimal system, each place to the left has 10 times the value of the place on its right.

It’s a Fact!It’s a Fact!Hundreds Tens Ones Tenths Hundredths Thousandth

sRead as

5 2 1 . 8 521 and 8 tenths

6 2 . 3 7 62 and 37 hundredths

0 . 0 0 5 5 thousandths

VocabularyVocabulary• Tenths –

• Hundredths –

• Thousandths –

• Equivalent decimals –

Decimal PointsDecimal Points• The decimal point separates the

whole number part of the decimal number from the fractional part of the decimal number.

• The places to the right of the decimal point end with ths. You say tens on the left side of the decimal point, but tenths on the right side.

To Read a DecimalTo Read a Decimal• Say the whole number first if there is

one.• Say “and” for the decimal point.• Say the rest of the number as a

whole number.• Say the place of the last digit.• For 62.37, say: “sixty-two and thirty-

seven hundredths”.

Equivalent DecimalsEquivalent Decimals• Adding a “0” to the right side of a decimal does

not change its value. These numbers are equivalent to each other.

• EX: 0.68 = 0.680 = 0.6800

• Adding a “0” immediately after the decimal DOES change its value. These numbers are not equivalent to each other.

• EX: 0.68 > 0.0680 > 0.00680

PracticePracticeWrite each number in standard form:36 hundredths _________________3 and 5 hundredths _____________

Write the digit for each place in 1,246.305.tens ____ tenths _____ thousandths ____

Name the place value of the digit 3 in each number.

45.3 __________ 0.13 ______________3,004 ________________

Ways to Write Numbers - ReviewWays to Write Numbers - Review• Word form: One billion, four hundred seven

million, seven hundred thirty-nine thousand

• Standard form: 1,407,739,000

• Expanded form: 1,000,000,000 400,000,000

7,000,000 700,000 30,000

9,000

Group PracticeGroup Practice

Math Workbook p. R 1-3

We will complete this together.

HomeworkHomeworkMath Workbook p. P 1-3.

This will be presented and noted as completed when I check your agenda

in the morning.