Early last month we looked at using the "Difference of Squares" concept to multiply two numbers surrounding a third central number (DiffSquares1). You may wish to review that lesson now if it's not fresh in your memory. Today we will go the other direction. This concept appeared a respectable 18 times this year (on average, once per test)--at a median (and average) placement of question # 48.
Number Dojo Level: 173