Decimals are numbers with place values even smaller than the ones place
How to use base ten (block) models to represent a decimal's place values (ones place, tenths place, hundredths place) using hundred blocks, tens sticks, and single blocks
How to write decimals in standard, expanded, and written forms.
Notes:
Decimals are numbers with place valueseven smaller than the ones place.
You can write a decimal point (.) at the end of any whole number
Writing digits to the right of the decimal point gives decimal place values
Ex. 1.5 shows decimal place of tenths; 2.64 shows decimal place of hundredths
The names of decimal place valuesmirror the names of whole number place values, but you need to add the "-ths" suffix to the end.
Each place value is 10 times MORE than the place on its right
Each place value is 10 times LESS than the place on its left
Ex. 111.11
hundreds
tens
one
.
tenths
hundredths
1
1
1
.
1
1
=100
=10
=1
=0.1
=0.01
Decimals can be represented with base ten (block) models
"One whole" or hundred block = ones place value
Column or stick = tenths place value
Single square = hundredths place value
Ex. 1.25
Decimals can be written in standard, expanded, and written forms:
Standard form: the decimal is written with number digits and a decimal point
Expanded form: the decimal is written as a sum of values for all place values
Written form: the decimal is written with words naming digits and place values from left to right
Ex. 12.34 (read aloud as "twelve point three four")
Standard form:
12.34
Expanded form:
10 + 2 + 0.3 + 0.04
Written form:
twelve and three tenths four hundredths
OR
twelve and thirty-four hundredths
Trailing zeroes (at the end/right of the number) are NOT important in decimals
Ex. 0.5 and 0.50 are equal (5 tenths = 50 hundredths)
Lessons
Introduction
a)
What are decimals?
b)
How to use base ten (block) models to represent decimals
c)
Standard, expanded, and written forms for decimals
1.
Naming decimal place values Write the place value of the underlined digit in the decimal number.
a)
14.9
b)
357.2
c)
0.68
d)
4.21
2.
Decimal digit values Fill out the value of each digit in the boxes. Then, write the expanded and written forms for the decimal.
a)
b)
c)
d)
3.
Decimals represented by base ten (block) models What is the decimal represented by the base ten (block) model?
a)
b)
c)
d)
4.
Equivalent decimal tenths and hundredths Using the list of decimals shown below: