Alex starts with a population of 1,000 amoeba that quadruples every hour for a number of hours, h. He writes the expression 1,000(4h) to find the number of amoeba after h hours.

Emma starts with a population of 1 amoeba that increases 40% every hour for a number of hours, h. She writes the expression (1 + 0.4)h to find the number of amoeba after h hours.

Use the drop-down menus to explain what each part of Alex’s and Emma’s expressions mean.