3.3 Adding and Subtracting Decimals

Focus … Adding and Subtracting Decimals to the thousandths position.

Explore pg. 96:

Add 5.763 + 3.94

First, use Front-End Estimation to estimate an answer.


Second, Add vertically by lining up the decimals; use 0 place holders so that each number has the same number of digits after the decimal.



The estimate was 8, so the calculated answer of 8.703 is reasonable.

Example pg. 97

Subtract 7. 456 - 3. 74

First, use Front-End Estimation to estimate an answer.


Second, Subtract vertically by lining up the decimals; use 0 place holders so that each number has the same number of digits after the decimal.



Practice
Page 98-99, 1-9 (Focus is # 4)