Getting Three Learning Objectives Understanding the terms of operations Using non-calculator methods to add, subtract and multiply whole numbers
Place four different numbers in a 2 by 2 grid
Example 5 7 3 4
MULTIPLY across and ADD 5 x 7 = 35 3 x 4 = 12 47
MULTIPLY down and ADD 5 x 3 = 15 7 x 4 = 28 43
The DIFFERENCE is 47 - 43 = 4
Task Try to find numbers that give a difference of 3. How many different grids give a difference of 3? Are there any theories you have on this?
Extension Try to make other differences? Can you make zero? What happens if you have two of the same number on the top row and two of the same number on the bottom row?