Squaring Two-Digit Numbers Ending in Five

This video tutorial explains a quick method to square two-digit numbers ending in five without using a calculator. The method involves multiplying the first digit by the next highest digit and appending 25 to the result. Examples include squaring 35, 65, and 95, demonstrating the method's consistency and simplicity.

What is the first step in squaring a two-digit number that ends in five?

• Multiply the first digit by itself

• Subtract 5 from the number

• Add 25 to the number

• Multiply the first digit by the next highest digit

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CCSS.6.EE.A.1

When squaring 35, what is the result of multiplying the first digit by the next highest digit?

• 18

• 15

• 12

• 9

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CCSS.3.OA.D.9

What are the last two digits of any squared number ending in five?

• 15

• 20

• 25

• 30

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CCSS.3.OA.D.9

For 65 squared, what is the product of the first digit and the next highest digit?

• 54

• 48

• 42

• 36

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CCSS.6.EE.A.1

In the example of 95 squared, what is the product of the first digit and the next highest digit?

• 72

• 81

• 99

• 90

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CCSS.6.EE.A.1