Exercise 10 Page 181

We are given the table that shows the times of four runners. We want to find the difference between Bolt's and Powell's times. Let's consider their times.

4 by 100 Meter Times
Runner	Time (s)
Carter	13.4
Frater	12
Bolt	12
Powell	11.7

We will subtract 11.7 from 12. To subtract decimals, we line up the decimal points so that place-value positions correspond. We will annex zeros so each place has a digit.

Now we subtract the decimals just as we would with whole numbers and place the decimal point in the answer.

The time difference between Bolt and Powell is 0.3 second.

We are given the table that shows the times of four runners. We want to find the combined time of all the runners.

4 by 100 Meter Times
Runner	Time (s)
Carter	13.4
Frater	12
Bolt	12
Powell	11.7

We will add all the times. Let's start by adding up the times that are whole numbers. 12 + 12 = 24Now, let's add to the result the time of Carter. To find the exact sum, we line up the decimal points so that place-value positions correspond. We will annex zeros so each place has a digit.

Now, we add the decimals, just as we would with whole numbers, and place the decimal point in the answer.

The combined time of Carter, Frater, and Bolt is 37.4 seconds. Next, we will add to this result Powell's time. Once again, we line up the decimal points so that place-value positions correspond.

Finally, we add the decimals, just as we would with whole numbers, and place the decimal point in the answer.

We found that the combined time of all runners is equal to 49.1 seconds.