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Copyright © 3P Learning – These resources have been created in partnership with Dr. Marian Small.
For more information visit
www.mathletics.comQuestions to facilitate the learning
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Why does it make sense that fewer coins can be worth more?
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Could you use 8 of the same coin for one group and 7 of the same coin for the other? Why do you
think that?
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Do you think there will be more valuable coins in the group of 7 coins or the group of 8 coins? Why do
you think that?
Scaffolding the learning
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Would it make sense to try 8 20¢ and 7 5¢? Why or why not?
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Could you make 3 coins be worth not much less than 2 coins?
What’s the point of this task?
Extending the learning
Students might explore whether even fewer than 7 coins could be worth more than 8 coins with close
values. For example, could 5 coins be worth just a little more than 8 coins?
Coins
Number
This task provides an opportunity for students to solve money problems and count coins as well as add
and subtract. It focuses students on the important concept that fewer coins can be worth more, because
different coins have different values.
The task encourages students to make conjectures, try lots of possibilities and use reasoning as they
figure out why the coin sets have to be different and how they can be different if the values are not that
far apart. In making those conjectures, students get a lot of practice in adding, subtracting and counting
coins, even though they are solving only one problem. Because the amounts must be close, more refined
reasoning is required. Some solutions include 8 5c vs 5 5c and 2 10c or 8 $1 vs 4 $2 and 3 5c pieces.