Mary Beth K. answered • 04/18/19
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Twenty-six years of teaching and tutoring; love it or leave it
Since you need two numbers that equal 20, you might want to look for pairs of numbers that equal 20 and also have a difference of 6. 1+19, 2+18, 3+17, 4+16, 5+15, 6+14, 7+13, etc. When one looks carefully at the numbers, one sees that the difference goes down by 2: 19-1=18, 18-2=16, 17-3=14,etc. When one gets to
13 and 7, one has the answer: 13+7 equals 20 and has a difference of 6.
