estimating decimals

Estimating Decimals

Rounding Rules

The digit to the right is greater or equal to 5, round up

The digit to the right is less than 5, round down

Rounding Jingle

4 and less let it rest,

5 and up bump it up

Guided Practice

Round each decimal to the nearest whole number.

5.39 =

43.27 =

16.892 =

51.508 =

99.83 =

Guided Practice

Round each decimal to the nearest tenth.

57.16 =

38.891 =

3.1974 =

17.753 =

29.987 =

Guided Practice

Round each decimal to the nearest hundredths.

4.468 =

3.761 =

38.997 =

Guided Practice

Estimate each sum or difference.

3.96 + 8.31 =

9.67 – 3.81 =

5.75 + 4.04 =

11.2 – 9.67 =

Problem Solving

Camera film costs $3.99 a roll. Wes needs 3 rolls to take pictures of the class party. He has $15. Does he have enough money?

Yes

Problem Solving

Flowers cost $5.99 a dozen. Faye wants to buy 2 dozen flowers. She also wants to buy a balloon that cost $4.50. Faye has $20. Does Faye have enough money to buy everything she wants?

Yes

Problem Solving

Eric bought pretzels for $1.89, peanuts for $2.39, and popcorn for $0.99. How much did he spend in all?

Answer: $5.27

Problem Solving

A party is scheduled to last one hour. Mrs. Call wants to show a video that lasts between 10 to 15 minutes. About how much time will be left for other activities?

Answer: about 45-50 minutes