Question

Ellen drove 357.9 miles. Her car gets about 21 miles per gallon. Which is the best estimate of how many gallons of gas Ellen used?

Answer 1

The best thing to do is to divide the amount she has driven (357.9) by the miles (21)
As you're looking for an estimate, you have to round them.
357.9 rounds to 360
21 rounds to 20
Therefore, you've got to divide them
360/20= 18
Therefore, Ellen has driven approximately 18 miles
Hope this helps :)

Answer 2

When looking for an estimate, you have to round your numbers 21 rounded would become 20 and 357.9 would become 360. So next you would divide the numbers.

360 ÷ 20 =  18

So, Ellen would have used approximately 18 gallons of gas.

Hope this helps you. :-)