Estimation in Decimal Multiplication & Division Problems
Solve multiplication and division problems that involve fractions.
Use rounding to check the answers to multiplication and division problems.
Number Framework Stage 8
Using Number Properties
Problem: “Estimate 0.503 x 58.7.”
Discuss why ½ x 60 = 30 is sensible.
Problem: “Martha gets 34.56 ÷ 0.98 = 33.8688 on her calculator. Is she correct?”
(Answer: Martha must be wrong as division by a number less than 1 makes the answer bigger.)
Problem: “Estimate 59.89 x 0.091.” (Possible answer: 59.89 x 0.091 ≈ 60 x 0.1, and 1 tenth of 60 = 6.)
Examples: Worksheet (Material Master 8–17).
Similar Resources
Sensible Rounding
Round whole numbers and decimals, with up to two places, to the nearest whole number, or tenth.
Use rounding to check the answers to multiplication and division problems.
Checking Multiplication by Estimation
Round whole numbers and decimals, with up to two places, to the nearest whole number, or tenth.
Use rounding to check the answers to multiplication and division problems.
Folding fractions and decimals
Solve multiplication and division problems that involve decimals.
Folding fractions and decimals
Solve multiplication and division problems that involve decimals.
