Question

the estimated product of 20.7 and 9.18, after rounding both factors to the nearest whole number, is .
the exact product of 20.7 and 9.18 has decimal places.

Explanation:

Round the factors to the nearest whole number

Using the Rounding Decimals knowledge point:

• For \(20.7\), the tenths digit is \(7 \ge 5\), so we round up to \(21\).
• For \(9.18\), the tenths digit is \(1 < 5\), so we round down to \(9\).

Calculate the estimated product

Using the Multi-Digit Multiplication knowledge point

$$ 21 \times 9 = 189 $$

Determine the number of decimal places in the exact product

Using the Decimal Places knowledge point

• \(20.7\) has \(1\) decimal place.
• \(9.18\) has \(2\) decimal places.
• The total number of decimal places in the product is:

$$ 1 + 2 = 3 $$

Answer:

Question 1

The estimated product of 20.7 and 9.18, after rounding both factors to the nearest whole number, is <blank>189</blank>.

Question 2

The exact product of 20.7 and 9.18 has <blank>3</blank> decimal places.