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 Order chips from enasco.com: search for thousandth chip. $13.95/1000

Representing Decimal Numbers Base 10 blocks Decimal Fraction 3 1000 Copy this page for handout. 0.407

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

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

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

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

Smallest to Largest 0.197 0.2 0.21 Discuss how appearances might be misleading, but all the small pieces in 0.197 do not add up to 0.2. While the screen may be misleading, the solid objects in their hands may be more convincing.

Adding Decimals Show the following with base 10 blocks. 0.21 + 1.483 0.36 + 0.47 Have teachers solve problems with blocks (no pencils!) before showing solutions.

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

Adding Decimals (2) 0.36 0.47 0.36 + 0.47

Adding Decimals (2) 0.36 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

Subtracting Decimals (1) 0.87

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 0.48 – 0.222

Multiplying Decimals 1.6 x 2 2 groups of 1.6

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

Multiplying Decimals (2) 0.1 x 0.78

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

Multiplying Decimals (2) 0.1 x 0.78 ? 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