Smiths have driven 400 miles which 5/8 of their trip. How much further do they have to drive
First, let's translate this into an equation.
400 is 5/8 of what number?
The missing number in this equation is the total trip miles.
400 x 8 is 3200
3200 divided by 5 is 640
640 is the total trip miles. Now we can take 3/8 of the 640 or we can just subtract 400 from 640.
640 minus 400 is 240. Let't check our answer.
640 times 3 is 1920. 1920 divided by 8 is 240.
How much further do they have to drive? The have to drive 240 more miles.