Highlight any 2x2 square within this grid.
Multiply the numbers in opposite corners.
Take the two numbers away.
Example
(54 x 45) - (44 x 55) = 2430 - 2420 = 10
Now try some other 2 x 2 squares within the grid
INVESTIGATE
Opposite Corners coursework
Consider this 10 x 10 tables grid
Highlight any 2x2 square within this grid.
Multiply the numbers in opposite corners.
Take the two numbers away.
Example
(54 x 45) - (44 x 55) = 2430 - 2420 = 10
Now ...