Remember: Compound interest pays on the interest already added, so growth speeds up. A flat garden adds the same each year. These gardens are made up, and nothing is promised.
Read and answer
Read the story first, then answer.
The Flat Patch and the SnowballAna and Sam each had one hundred pretend coins to plant, and Pebble Town had two made-up gardens whose extra coins were called interest. Sam liked things steady, so he picked the Flat Patch, which added ten coins each year. It paid only on the coins he planted, and that is simple interest. Ana picked the Snowball Garden, which added one coin for every ten inside and counted the new coins too, and that is compound interest. In year two, Ana's garden held 110, so it added eleven, while Sam's Flat Patch added ten again. Ana had 121 to Sam's 120, one coin ahead, and after five years she held 160 while he held 150. After ten years, Ana held 256 and Sam held 200. Why did Ana pull ahead? Year three began with 121 coins. Twelve new coins came: ten from the planted hundred, and two from the interest coins, so interest was earning interest!
1
How many coins does Sam's Flat Patch add each year?
One coinTen coinsEleven coins
2
Look at the table. In year 5 Sam holds coins.
3
In year two, Ana's Snowball Garden holds 110 coins, which is eleven tens. How many new coins does it add?
TenTwelveEleven
4
Year 2: Ana holds 121 and Sam holds 120. Ana is coin ahead.
5
After 10 years Ana holds 256 and Sam holds 200. Ana leads by coins.
6
Sam's Flat Patch pays interest on the interest coins too.
TrueFalse
7
Year three starts with 121 coins in Ana's garden. Where do her 12 new coins come from?
Ten from the planted hundred, and two from the interest coinsAll twelve from the planted hundredAll twelve from the interest coins
Match, order and fix
8
Join each one to what it does.
1Flat Patch
2Snowball Garden
3Simple interest
4Compound interest
Ainterest that earns its own interest
Bpays only on the planted coins
Cadds the same ten coins every year
Dadds more new coins each year
9
Circle each sign of compound interest.
New coins that get bigger each yearThe same new coins every yearInterest that earns interestLeaving the new coins in the gardenTen coins a year on a hundred planted
10
Number the story.
Ana and Sam plant 100 coins each
Year five: Ana has 160, Sam has 150
Year ten: Ana has 256, Sam has 200
Year two: Ana has 121, Sam has 120
11
Sam says: ten coins a year is the same as compound interest. Is Sam right?
YesNo
12
Stretch: Ana's garden holds 133 coins. The new coins next year are .
13
Why does a snowball garden grow faster the longer it runs?
14
Draw a snowball rolling downhill, small at the top and big at the bottom.
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