8 2/5 kilometer mountain. 2 1/4 kilometers+1 7/8 kilometers+1 2/9 kilometers. How much farther do they have to travel to reach the peak of the mountain?

Question

Adding fractions

Answer 1

To add the mixed numbers, add the whole numbers first: 2+1+1=4.

Now to add the fractions. Common denominator is 72.

¼=18/72, ⅞=63/72, ²⁄₉=16/72, added together is (18+63+16)/72=97/72=1²⁵⁄₇₂.

So the total distance so far is 4+1²⁵⁄₇₂=5²⁵⁄₇₂.

We now need to subtract this from 8⅖.

Subtract 5 from 8 first=3.

To subtract the fractions we need the common denominator of 5 and 72, which is 360.

⅖=144/360 and ²⁵⁄₇₂=125/360.

So (144-25)/360=19/360. So the distance to go is 3¹⁹⁄₃₆₀ km.