Using Base 10 Blocks to Model Decimal
Concepts & Operations
Joyce Bishop
ROE 10 mathgarden.weebly,com

Using Familiar Base 10 Blocks to Model Decimal
Numbers
• flat = 1
• Long = 0.1
• small cube = 0.01
• small flat (chip) = 0.001
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Representing Decimal Numbers
Base 10 blocks Decimal Fraction
3
1000
0.407

Representing Decimal Numbers
Base 10 blocks Decimal
1.17
Fraction
1 17
100

Representing Decimal Numbers
Base 10 blocks Decimal
1.17
Fraction
1 17
100
0.003
3
1000

Representing Decimal Numbers
Base 10 blocks Decimal
1.17
0.003
0.407
Fraction
1 17
100
3
1000
407
1000

Comparing Decimals
Represent the following with base 10 blocks and put them in order from smallest to largest:
0.2
0.197
0.21

Representing Decimal Numbers
0.2
0.197
0.21

0.197
Smallest to Largest
0.2
0.21

Adding Decimals
Show the following with base 10 blocks.
0.21 + 1.483
0.36 + 0.47

0.21 + 1.483
0.21
Adding Decimals (1)
1.483
0.21 + 1.483= 1.693

0.36
Adding Decimals (2)
0.47
0.36 + 0.47

0.36
Adding Decimals (2)
0.47
0.36 + 0.47
0.36 + 0.47 = 0.83

Subtracting Decimals
Subtract the following:
0.87 – 0.26
0.48 – 0.222

0.87
Subtracting Decimals (1)

Subtracting Decimals
0.87 – 0.26 = 0.61

Subtracting Decimals (2)
Subtract the following:
0.48 – 0.222

Subtracting Decimals (2)
0.48 – 0.222

Subtracting Decimals (2)
0.48 – 0.222
0.48 – 0.222 = 0.258

1.6
x 2
Multiplying Decimals
2 groups of 1.6

Multiplying Decimals
1.6
x 2
Trade to make another unit.
1.6 x 2 = 3.2

0.1 x 0.78
Multiplying Decimals (2)

0.1 x 0.78
Multiplying Decimals (2)
? 0.1 of 0.1 ? 0.1 of 0.01

0.1 x 0.78
Multiplying Decimals (2)
? 0.1 of 0.1
0.1 of 0.01
(7 x 0.1 x 0.1) + (8 x 0.1 x 0.01) = 0.07 + 0.008 = 0.078

Dividing Decimals (1)
Ellen had 0.6 m of yarn. She wanted to divide it into 2 equal pieces. How long should each piece be? Show your answer with base 10 blocks.
0.6 ÷ 2

Dividing Decimals (1)
Ellen had 0.6 m of yarn. She wanted to divide it into
2 equal pieces. How long should each piece be?
Show your answer with base 10 blocks.
0.6 ÷ 2
0.6 divided into 2 equal groups.
How many in each group?
0.6 ÷ 2 = 0.3

Dividing Decimals (2)
Ryan has 1 kg of fudge. He plans to wrap it in packages with 0.2 kg in each package. How many packages will he have?
1 kg = 10 x 0.1 kg

Dividing Decimals (2)
Ryan has 1 kg of fudge. He plans to wrap it in packages with 0.2 kg in each package. How many packages will he have?
1 kg = 10 x 0.1 kg 10 (0.1) divided into groups of 0.2
How many groups?
1 ÷ 0.2 = 5