Question

Estimate and then calculate. 2.34 × 6.9

Answer 1

Rounding the first number, you have

`2.34\approx2.3\approx2`

because the number is rounded down if the digit to the right is less than 5.

Rounding the second number, you have

`6.9\approx7`

because the number is rounded up if the digit to the right is greater than 5.

Therefore, estimating and calculating, you have

`2.34\cdot6.9​\approx2\cdot7=14`