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Regroup Factors to Make a Large Product Easier

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Large Numbers Around Us · Multiplication shortcuts · 3:15

You'll learn: Reorder and regroup factors so that pairs like 4 × 25 or 8 × 125 make a long product easy.

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Regroup Factors to Make a Large Product Easier

3:15

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Regroup Factors to Make a Large Product Easier

You'll learn: Reorder and regroup factors so that pairs like 4 × 25 or 8 × 125 make a long product easy.

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Same topic

Multiplication shortcuts

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Multiply by 5, 25 or 125 Using 10, 100 or 1000
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Multiply by 5, 25 or 125 Using 10, 100 or 1000
You'll learn: 5 = 10 ÷ 2, 25 = 100 ÷ 4 and 125 = 1000 ÷ 8, so multiply by a power of ten and divide: one shortcut, three cases.

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Predicting product length

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What Patterns Appear in Repeated-Digit Products?
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What Patterns Appear in Repeated-Digit Products?
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Calculations revealing large-number facts

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What Does a Large Calculation Tell Us About a Real Quantity?
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What Does a Large Calculation Tell Us About a Real Quantity?
You'll learn: Turn the result of a large calculation back into a real quantity with sensible units and judge its size.

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Estimation thought-experiments

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Could a Lakh Buses Hold a City's Population?
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Could a Lakh Buses Hold a City's Population?
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Could You Reach the Moon in Ten Years?
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Toothpick-digit exploration

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Make the Largest and Smallest Numbers with Fixed Toothpicks
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Expressions and their values

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Turn a Calculation Story into an Arithmetic Expression
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Comparing expressions through reasoning

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Compare Two Expressions Without Calculating Everything
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Compare Two Expressions Without Calculating Everything
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Change an Expression While Keeping Its Value
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Next topic

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How Do Brackets Change a Calculation's Meaning?
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How Do Brackets Change a Calculation's Meaning?
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Identifying terms

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Rewrite Subtraction as Addition of an Opposite
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