MGSE5.NBT.5
Fluently multiply multi-digit whole numbers using the standard algorithm (or other strategies demonstrating understanding of multiplication) up to a 3-digit by 2- digit factor.
THREE STRATEGIES
Strategy: Standard Algorithm
Vocabulary:
Algorithm - a set of steps or rules for solving a problem
How it works:
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Start with the digit in the bottom ONES place and multiply that digit with all of the top numbers from right to left
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Move under your first product and put a zero in the ones place
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Multiply the bottom TENS place digit by ALL the top numbers from left to right.
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If you have no more digits to multiply on the bottom, add your two products for your final answer. If you have another digit in the bottom HUNDREDS place, move under your 2nd product and put a zero in the ones AND tens place. (2 zeros)
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Multiply the bottom HUNDREDS place digit by ALL the top numbers from left to right.
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ADD all 3 rows (products) for your final answer.
Strategy: Box or area method
Vocabulary:
Area - length x width
How it works:
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Expand your numbers
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Fill your boxes by multiplying the nonzero digits. Then count up all the zeros to add them behind the whole number
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Stack all of the numbers from your boxes together lined up by place value.
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Add them together
Strategy: Partial Products
Vocabulary:
Product-answer to a multiplication problem
Partial-incomplete
How it works: Solve for all the partial products then add them together.
