Estimating Products

Question

Estimate the product of 115 × 9.
Round the factors.
115 → ____
9 → 10
Multiply the first digits.
1x1 = ______
There are three zeros in the factors, so we place three zeros at the end of the product.
1,000

Answer 1

To estimate the product of 115 × 9, we follow these steps:

1. Round the factors:

   • 115 is rounded to 120.
   • 9 is rounded to 10.

2. Multiply the rounded numbers:

   • 120 × 10.

3. Multiply the first digits:

   • 1 x 1 = 1.

4. Count how many zeros are in the factors:

   • 120 has 2 zeros, and 10 has 1 zero, so there are a total of 3 zeros.

5. Combine the result:

   • 1 followed by 3 zeros gives us 1,000.

So the estimated product of 115 × 9 is 1,000.