Problem

Materials:

  • paper
  • pencil

On Friday at 9 am, the magic plant was 2 centimetres tall.

a small plant with a single stalk and two leaves
Each day, the plant’s height doubled and it was two times as tall as the day before.

a plant with a single stalk and 6 leavesHow tall was it on Monday at 9 am?

Possible Hints/Questions:

  • Maybe you could draw a number line that goes up and down to help show how much the plant grew?
  • What does “two times as tall” mean?
  • How tall was the plant on Saturday at 9am?
  • How tall was the plant on Sunday at 9am?

Possible Extension:

  • How tall do you predict the plant will be on Thursday? Find out if you are right.

Adapted from nrich.maths.org