7 children play the piano.

8 children play flute.
5 children do not play an instrument
How many fewer children do not play an instrument?

7 + 8 = 15

15 - 5 = ?

How is the answer 10? The 15 total all play instruments. The balance of 10 are of students who "play" instruments.

To find the number of children who do not play an instrument, we need to subtract the number of children who play an instrument from the total number of children.

The total number of children can be found by adding the number of children who play the piano, the number of children who play the flute, and the number of children who do not play an instrument.

Let's calculate it step by step:

1. Calculate the total number of children who play the piano and the flute:
Total children who play an instrument = Children who play the piano + Children who play the flute
Total children who play an instrument = 7 + 8 = 15

2. Calculate the total number of children:
Total number of children = Total children who play an instrument + Children who do not play an instrument
Total number of children = 15 + 5 = 20

3. Finally, calculate the number of children who do not play an instrument:
Number of children who do not play an instrument = Total number of children - Total children who play an instrument
Number of children who do not play an instrument = 20 - 15 = 5

Hence, there are 5 fewer children who do not play an instrument.