Answer:
7 people
Explanation:
(21 cookies)/(3 cookies/person) = 7 person
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If you're really challenged figuring this out, you can count out 21 of some object—such as pennies, scraps of paper, or even cookies—and deal them into piles of 3 each. Then count the piles. Working with actual physical objects can often give you mathematical insight not obtainable any other way.
Each pile subtracts 3 from the original amount. We use the arithmetic operation "division" to simplify repeated subtraction.
Knowing number facts such as 3×7 = 21 is very helpful to solving problems of this nature.