Hi Rebecca,

Linear growth means that it grows by the same amount in each time step. For example you might have something that is 5 inches long on Monday morning and then 8 inches long on Tuesday morning and then 11 inches long on Wednesday morning and so on. So it is growing by 3 inches a day. If you draw a graph with the days on the horizontal axis and the height in inches on the vertical axis then the points lie on a line. This is why it is called linear growth.

Some growth is not linear. If you have a checker board and put 1 penny on the first square, a stack of 2 pennies on the second square, a stack of 4 pennies on the third square, a stack of 8 pennies on the fourth square, that is you double the number of pennies in the stack at each step, then the growth is not linear.

Penny