About this video
Beatrice buys 7 pizzas with 12 pieces each for 16 people who each eat 4 pieces. The video multiplies 7 × 12 = 84 total pieces, then 16 × 4 = 64 pieces eaten, and subtracts to find 20 extra pieces.
You'll be able to
- break a multi-step word problem into smaller steps.
- use multiplication to find a total from groups of equal size.
- subtract to find how many are left over.
Key words
- total
- The whole amount when everything is put together.
- extra
- The amount left over after everyone has had their share.
Transcript
Beatrice is ordering pizzas for a party. Each pizza is cut into 12 pieces. Beatrice wants to have enough pizza so that each person can have 4 pieces. And 16 people will be at the party. A lot of information in this problem. If Beatrice buys 7 pizzas, how many extra pieces will there be after each person eats 4 pieces?
So to do this, let's think about how many total pieces she will have. And then let's think about how many total pieces will be eaten by the 16 people. And then we'll figure how much that she had extra. So first, let's think about how many total pieces. And I encourage you to pause the video and try to figure it out yourself.
She ordered 7 pizzas. How many total pieces are there going to be? Well, you have 7 pizzas. 7-- that's the number of pizzas. And if you have 12 pieces per pizza, you multiply by 12 to get the total number of pieces. So this is number of pieces per pizza. And 7 times 12 is equal to 84 total pieces.
So that's how many pieces she's got. Now let's think about how many get eaten by the 16 people. So you have 16 people. 16-- that's the number of people. And this little symbol, that's shorthand for number. 16 people, and they each eat 4 pieces. So 16 people times 4 pieces per person.
So number of pieces per person. 16 times 4 is 64. So that's 64-- not 84-- 64 pieces are eaten by the 16 people. So how much does she have left over? Well, if you start with 84 pieces and 64 get eaten, 84 minus 64 is 20. We deserve a drum roll now. You have 20 extra pieces after everyone eats their share.
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