fractions

posted by on .

Ok I'm a Mom trying to figure this out to help my foster daughter it's harder because english is her second language. please explain how you get the answer I just could never grasp fractions and I want to help her thanks also I posted the first one but really need help with the second:

1. Ian and his dad went fishing they took 81 fleas along as bait. when they returned home 1/9 were left how many sand flea did they use? She came up with 72 as her answer(she divided 81 by 9 =9 then subtracted it from 81. Is this correct?

2. It took 20 minutes to dig the sand fleas. they got 7/9 in the last 8 minutes. How many in the first 12 minutes? She was thinking she needed to divide 81 by 9 and then multiply the 7 by 9? She got me confused, any help is much appreciated.

• fractions - ,

The first:

left=81/9=9 fleas left
so they used....81-9
she did it correctly. Good.

Now on the second.
in the last 8 min they got (7/9 * 81)=63

so in 12 min, they must have got the rest, 81-63