this makes no sense to me and won't to my child either. the instructions for solving, are try 3 numbers that add to the total with 2 numbers equal and the other 8 less then revise numbers till you get the answer. the question is: Jan, Mya And Sara ran a total of 64 miles last week. Jan and Mya ran the same number of miles. Sara ran 8 less miles than Jan and Mya. How many miles did Sara run?

Let x be the number of miles run by Jan.

Let x be the number of miles run by Mya.
Let x-8 be the number of miles run by Sara.

* using the following equations, we have:
x+x+x-8=64
3x-8=64
3x=64+8 * since we transposed -8 on the right side, it became +8.
3x=72 * in order to get the value of x, we divide both side by 3.
x= 24 miles.

Jan and Mya ran 24 miles each while Sara, x-8 (24-8), run 16 miles.

If we add the 3 numbers, 24 mi, 23 mi, and 16 mi, the total will be 64 miles.