Estimating Decimal Products

Front

What is estimating in mathematics?

Back

Estimating is the process of finding an approximate value that is close to the actual value, often used to make calculations easier.

Front

How do you estimate the product of two decimal numbers?

Back

Round each decimal to a whole number or a simpler decimal, then multiply the rounded numbers.

Front

Estimate 7.8 x 4.5 by rounding.

Back

Round 7.8 to 8 and 4.5 to 5. The estimate is 8 x 5 = 40.

Front

Is the estimate of 7.8 x 4.5 = 40 reasonable?

Back

Yes, because the actual product is around 35.1.

Front

Estimate 5.19 x 7.912 by rounding.

Back

Round 5.19 to 5 and 7.912 to 8. The estimate is 5 x 8 = 40.

Front

Estimate 0.003 x 2.9.

Back

Round 0.003 to 0 and 2.9 to 3. The estimate is 0 x 3 = 0.

Front

What is the estimated product of 99.7 x 12.2?

Back

Round 99.7 to 100 and 12.2 to 12. The estimate is 100 x 12 = 1200.

Front

Estimate 0.007 x 1.02.

Back

Round 0.007 to 0 and 1.02 to 1. The estimate is 0 x 1 = 0.

Front

Why is estimating products useful?

Back

Estimating helps to quickly assess the reasonableness of answers and simplifies calculations.

Front

What is a reasonable estimate for 8.5 x 3.6?

Back

Round 8.5 to 9 and 3.6 to 4. The estimate is 9 x 4 = 36.