High School

Paul wins a 1500-metre race in 4.67 minutes.

(a) Estimate his average speed in metres per minute.

(b) Use a calculator to find his actual average speed in metres per minute.

Answer :

Answer: See below

Step-by-step explanation:

A) The best way to estimate average speed is to make sure that each number is a whole number (with no decimals). This will make division much easier. The number of meters is already a whole number, but to make the number of minutes a whole number, we must round. Because the number after the decimal is greater than 5, that means we will round up, making the value of minutes 5. Now we can estimate 1500 metres/5 minutes = 300 metres/minute

As a little rounding tip, you can use this mnemonic: 4 and below, let it go (round down). 5 and above, give it a shove (round up)!

B) To do this part, we can simply plug the following into the calculator:

1500 metres/4.67 minutes = 321.2 metres per minute

Hope this helps!