Question

David drove 634 miles on 26.6 gallons of gas. What was his gas mileage, rounded to the nearest mpg?

Answer 1

24 mpg

Explanation:

Shortcut method:`" "634-:26.6 = 23.835` to 3 decimal places

As the digit to the right of the decimal point satisfies the condition of greater than or equal to 5 we round up. That is the digit to the left of the decimal point has 1 added to it.

So `23.835 -> 24` to the nearest miles per gallon.
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
`color(brown)("This is why the shortcut method works:")`

Using ratio`->("distance")/("fuel used") ->634/26.6`

But we need the distance for 1 gallon. So we need to change the 26.6 to 1

`("count of miles")/("count of gallons")->(634-:26.6)/(26.6-:26.6) =23.835/1`