NRICH: Magic Potting Sheds

Mr McGregor has a magic potting shed. Overnight, the number of plants in it doubles. He would like to put the same number of plants in each of three gardens, planting one garden each day.

On the first day he puts some plants in the shed. Overnight, they double.
The next day he plants some in one of the gardens. The remaining plants double overnight.
The next day he plants some in a second garden, and again the remaining plants double overnight.
On the final day he plants all the remaining plants in the third garden.

Use the interactivity  to help you work out how many plants he should put in the potting shed on the first day, and how many he should plant in each garden.
Can you find more than one solution?
What do the solutions have in common?
Can you find the smallest number of plants he could use?

f you have enjoyed this problem, you might like to move on to More Magic Potting Sheds .

Math Topics
Multiplication & Division
Middle School, High School
6th Grade, 7th Grade, 8th Grade, 9th Grade

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NRICH (University of Cambridge)

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Online Interactive Activity

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