Estimating Products

Question

Estimate the product of 115 x 9.
Round the factors.
115 -> _
9 -> 10
Multiply the first digits.
1 x 1 = _
There are three zeros in the factors, so we place three zeros at the end of the prodect.
1,000

Answer 1

Your estimation process is close, but let's clarify a bit:

1. Round the factors:

   • 115 rounds to 120 (since it's closer to 120 than to 100).
   • 9 rounds to 10.

2. Multiply the rounded factors:

   • \( 120 \times 10 \).

3. Calculate:

   • \( 120 \times 10 = 1,200 \).

So the estimated product of 115 x 9 is approximately 1,200.