Round to the greatest place value to make it easier to compute mentally. In this case, round 13.92 to the nearest ten and 2.7 to the nearest whole number.
Estimation: 30 Product: 10* 3=30
Practice makes perfect
We want to estimate the given product.
13.92 * 2.7
To make our estimation, we will round each factor to the greatest place value. This makes it easier to use mental math. We need to follow a couple steps.
Look at the digit to the right of the place that is being rounded to.
If the digit is less than 5, then the number in the rounded place remains the same.
If the digit is 5 or greater, add 1 to the number in the rounded place.
After rounding, remove any decimal digits and convert into 0 the non-decimal digits to the right of the place value being rounded.
In our case, we want to round 13.92 to the nearest ten and 2.7 to the nearest whole number. Therefore, for 13.92, the place that we are rounding to is the tens place, so we will look at the number in the ones place. Similarly, for 2.7, the place that we are rounding to is the ones place, so we will look at the number in the tenths place.
