24 3/7 minus 15 6/7

Question

Show the steps you would use to compute mentally.I don't understand

Answer 1

24 3/7 - 15 6/7

23 10/7 - 15 6/7         borrow

8 4/7

Answer 2

Change both into improper fractions. 

 

171/7 - 111/7 = 60/7 

 

Which we can change to 8 4/7 

 

 

Answer 3

Let's write it this way:

   24 3/7

 - 15 6/7

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Now, subtract right-to-left as normal.  Since 6/7 is larger than 3/7, borrow 1=7/7, so you now have:

    23  10/7

 -  15    6/7

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     xx   4/7    [note that 5 is greater than 3, so you must borrow again:

 

       1

      13  10/7

   -  15    67

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        8   4/7