Doing · Money sense
20 min · pencil, calculator (optional)
★★★
Penny doubled or $500?
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Would you rather have $500 now, or a penny that doubles? Day 1 is 1¢, day 2 is 2¢, day 3 is 4¢… What do you get on day 20?
- Write your guess at the bottom first.
- Fill in each day by doubling. Then turn day 20 into dollars.
Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Day 7
Day 8
Day 9
Day 10
Day 11
Day 12
Day 13
Day 14
Day 15
Day 16
Day 17
Day 18
Day 19
Day 20
My guess:
Day 20 in dollars: $
Grown-up corner
Why it matters: Doubling starts slow and then explodes. This is how savings and interest can grow over time.
- On which day did the penny pass $500?
- Why does it grow so fast at the end?
Extend it: Try it with the smallest coin where you live. The doubling works the same way.
My brain felt: ☐ easy ☐ just right ☐ stretchy
One thing I learned: ________________________
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