Remember: Snowball pays the smallest pile first. Avalanche pays the costliest first. One saves a few coins and one wins sooner, so ask a grown-up to help weigh them.
Read and answer
Read the story first, then answer.
Two plans in Pebble MillIn the pretend town of Pebble Mill, Lio owed coins on two things: the bike pile was twenty coins and the games pile was ten. The bike pile added one extra coin for every full ten owed. The games pile added one for every full twenty, so it added nothing yet. Lio could pay eight coins a month, with one coin going to each pile and the rest to just one of them. Mara said, "Smallest pile first," and that plan is called the snowball. Teo said, "Costliest pile first," and that one is called the avalanche. With the snowball, the games pile was gone in month two, and the bike pile was gone in month five, and Lio paid thirty-six coins in all. With the avalanche, the bike pile fell fast: fifteen, nine, two, gone in month four, and Lio paid thirty-three coins in all, three fewer. The bike pile adds the most extra, so shrinking it first gives it less time to add more. The snowball gets its first win sooner, and a quick win can feel good. Which to choose is a personal call a grown-up can help weigh.
1
Look at the table. Which plan pays fewer coins in all?
The snowballThe avalancheThey pay the same
2
The snowball pays 36 coins and the avalanche 33. The avalanche pays coins fewer.
3
The snowball pays the smallest pile first.
TrueFalse
4
In month one the snowball puts 7 of the 8 coins on the games pile and on the bike pile.
5
The avalanche's bike pile goes 20, 15, 9, then after month three.
6
Join each one to its plan.
1Mara's plan
2Teo's plan
3The snowball's first win
4The avalanche's first win
Amonth four
Bcostliest pile first
Csmallest pile first
Dmonth two
Think, fix and plan
7
Why does the avalanche pay fewer coins in all?
The costliest pile gets less time to growIt has better luckThe bike pile is free
8
Why do some people pick the snowball?
It always pays fewer coinsIt skips the extraThe first win comes sooner, and a quick win can feel good
9
Circle every true sentence.
Both plans use the same 8 coins a monthThe snowball pays fewer coinsThe games pile added no extra at the startBoth plans clear both pilesThe avalanche's first win is in month two
10
Number the avalanche's bike pile from first to last.
2 coins after month three
15 coins after month one
Gone in month four
9 coins after month two
11
Lio says: the snowball pays fewer coins because its first win comes sooner. Is Lio right?
YesNo
12
The snowball takes 5 months. Four months of 8 coins is 32, so month five pays coins to make 36.
13
Write one thing a grown-up could help Lio weigh when picking a plan.
14
Draw a pile of 20 coins and a pile of 10. Mark which pile the snowball pays first.
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Answer key · Set A
Snowball or avalanche?
1The avalanche The avalanche pays 33 and the snowball 36. Same piles, same 8 coins a month.
23 36 − 33 = 3.
3True Mara's snowball starts small. Teo's avalanche starts with the costliest pile.
41 One coin goes to each pile and the rest to just one of them, so 7 + 1 = 8.
52 The bike pile falls fast, and it is gone in month four.
61-C, 2-B, 3-D, 4-A Mara's snowball and Teo's avalanche win first in month two and month four.
7The costliest pile gets less time to grow The bike pile adds the most extra, so shrinking it first gives it less time to add more.
8The first win comes sooner, and a quick win can feel good The snowball's first win is in month two. It pays 3 more coins in all, but it can keep a person going.
9Both plans use the same 8 coins a month, The games pile added no extra at the start, Both plans clear both piles Both plans pay 8 a month and clear both piles, and the games pile adds one only for every full twenty. The snowball pays 36, and the avalanche's first win is month four.
103, 1, 4, 2 It goes 15, 9, 2 and then it is gone.
11No A sooner win is not fewer coins. The snowball pays 36 and the avalanche 33.
124 36 − 32 = 4. Only 4 coins were left on the bike pile.
13Your own words: a grown-up reads it.
Mark each answer, count the right ones and write the score on the sheet.