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Ages 10+ · Money · Investing and growing
The cost of waiting a year
How far ahead Ivy is, in coins05101520251011121231341451661771982192310by year
The gap between Ivy and Ben never closes. It grows every year.
The big ideaA year of waiting leaves a gap that never closes, because it is the biggest year.

How it works

Ivy planted 100 pretend coins today. Ben waited one year, then planted his 100, exactly one year behind.

Both gardens follow the same rule, so Ben's garden is always where Ivy's was a year before.

Ivy always holds one extra year of growth, and the last year is the biggest year. So the gap keeps growing.

Ivy• Plants 100 today• Has 110 after one yearBen• Plants 100 a year later• Always one year behind
Ivy plants now. Ben plants a year later.
Coins in year 10050100150200250300256Ivy233Bencoins
In year ten, Ivy leads by 23 coins.

Example 1: Ben is always one year behind

  1. After one year, Ivy has 110 and Ben plants his 100.
  2. Both gardens follow one rule.
  3. So Ben's garden is always where Ivy's was a year before.

Example 2: The gap in year five

  1. Ivy holds 160 and Ben holds 146.
  2. 160 − 146 = 14
  3. The gap is 14 coins.

Example 3: The gap in year ten

  1. Ivy holds 256 and Ben holds 233.
  2. 256 − 233 = 23
  3. The gap grew from ten coins in year one to 23 in year ten.

Example 4: Catching up

  1. Ben could plant 110 coins instead of 100.
  2. 110 − 100 = 10
  3. That one year cost ten coins, and then the gardens match every year.

Words to know

gap
How many coins one garden is ahead of the other.
behind
Starting one year later than the other garden.
growth
The new coins a garden adds in a year.

Watch out

Try it

  1. Year 2: Ivy has 121 and Ben has 110. What is the gap?
  2. Year 5: Ivy has 160 and Ben has 146. What is the gap?
  3. Does the gap close by itself if Ben waits?
  4. Ben plants 110 a year late. How do the gardens compare?
Answers: 1. 11 coins · 2. 14 coins · 3. No · 4. The same from then on
Try at homeWith a grown-up, talk about something where starting one year earlier would have mattered, like a skill, a hobby or a habit. Why did that year matter?
For grown-upsTalk about something where starting one year earlier would have mattered, like a skill, a hobby or a habit. Why did that year matter? The numbers here come from a made-up garden, and nothing is promised for any real money.
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