Decimals

Place Value, Expanded and Standard Forms

Decimal Word Names

• Decimal word names always end in “-th” or “-ths”

one tenth

four hundredths

Decimal Word Names

• Decimal word names always end in “-th” or “-ths”

one tenth

four hundredths

Representing the decimal

• The decimal is represented by the word “and” when writing and saying decimals in words.2.1 = two and one tenth

Representing the decimal

• The decimal is represented by the word “and” when writing and saying decimals in words.2.1 = two and one tenth

What decimals are

• Decimals show amounts between two consecutive counting numbers (3,4…)

0.45 is between 0 and 1

3.861 is between 3 and 4

25,196.8 is between 25,196 and 25,197

How to write decimals numbers greater than one

• To write a number containing a whole number and decimal fowllow these steps:

A. Write the whole number in words

B. Write “and”

C. Write the numbers shown in the decimal

D. Write the last place a digit occupies in the decimal (the farthest right)

How to write decimals numbers greater than one

• To write a number containing a whole number and decimal fowllow these steps:

A. Write the whole number in words

B. Write “and”

C. Write the numbers shown in the decimal

D. Write the last place a digit occupies in the decimal (the farthest right)

32.46A. thirty-two

B. and

C. forty-six

D. hundredths

thirty-two and forty-six hundredths

To write decimals in expanded form

• Write the place individually

5.306 =

To write decimals in expanded form

• Write the place individually

5.306 = 5

To write decimals in expanded form

• Write the place individually

5.306 = 5 + 0.3

To write decimals in expanded form

• Write the place individually

5.306 = 5 + 0.3 + 0.006

To write decimals in expanded form

• Write the place individually

5.306 = 5 + 0.3 + 0.006

To show the value of the decimal places in expanded form

• Multiply the digit by the value of the corresponding place

5.306 =

To show the value of the decimal places in expanded form

• Multiply the digit by the value of the corresponding place

5.306 = (5 x 1)

To show the value of the decimal places in expanded form

• Multiply the digit by the value of the corresponding place

5.306 = (5 x 1) + (3 x 0.1)

To show the value of the decimal places in expanded form

• Multiply the digit by the value of the corresponding place

5.306 = (5 x 1) + (3 x 0.1) + (6 x 0.001)

To show the value of the decimal places in expanded form

• Multiply the digit by the value of the corresponding place

5.306 = (5 x 1) + (3 x 0.1) +(6 x 0.001)

To put a number in standard form

• To put a number in standard (numeral) form from expanded form, just add all places together.

8 + 0.1 + 0.05 + 0.003

To put a number in standard form

• To put a number in standard (numeral) form from expanded form, just add all places together.

8 0.1 0.05 0.003

To put a number in standard form

• To put a number in standard (numeral) form from expanded form, just add all places together.

80.10.050.003+

To put a number in standard form

• To put a number in standard (numeral) form from expanded form, just add all places together.

80.10.050.003+8.153

To put a number in standard form

• To put a number in standard (numeral) form from expanded form, just add all places together.

80.10.050.003+8.153

Note: No place should have more than one digit in this addition