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 Question from Arlene, a parent: The Whites and Sulphurs are one major family of butterflies. There are about 720 varieties. Eleven times more Whites and Sulphurs live outside North America, mostly tropical Asia and Africa, than live inside North America. How many of this family of butterflies live in North America? How many live in the rest of the world?

Hi Arlene,

The subject line of your email was "Guess and Check". that is certainly the way I would solve this.

Imagine that you can gather all the Whites and Sulphurs in North America in one place. In my diagram they are all inside the red dot in North America.

Since there are 11 times as many outside North America, imagine they are gathered into 11 equal sized locations as illustrated in the diagram. There are 720 varieties in total in these locations. How many are in each location?

Penny

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