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Cindy says she found a shortcut for doing multiplication problem. when she multiplies 3x24 she says 3x4is 12 or one ten and 2 ones. then there's just 2 tens left in 24, so add it up and you get. 3 tens and 2 ones. do you think Cindy's shortcut works? explain your thinking in words, and justify your response using model or partial products

Verified Answer :

no because 3x24=72 whereas cindy got 32. for cindy's "trick" to work, she would also have to multiply the remaining 2 tens by 3, getting a product of 60, and adding it the the previous product of 12.

Cindy's shortcut will not work because;

She made a mistake by not multiplying the 2 tens by 3 .

  • She wants to multiply 3 × 24.

Now, for 24; 2 is the tens digit and 4 is the units digit.

This means according to partial products, we can rewrite 24 as; (2 × 10) + (4 × 1)

Now, to multiply 3 by (2 × 10) + (4 × 1) gives the expression;

3[(2  × 10) + (4 × 1)]

  • Using distributive property to distribute 3 into the bracket, we have;

3(2  × 10) + 3(4 × 1)

  • For her first step, she did; 3 × 4 = 12

This corresponds with the solution i got which is 3(4 × 1) = 12.

Now, the second part of the solution is; 3(2  × 10) = 60

But she just used 2 tens which is (2 × 10) = 20.

  • She now proceeded to add the 2 tens to the 1 ten and 2 ones instead of adding 6 tens to the 1 ten and 2 ones .

This means she failed to multiply 2 tens by 3 and that was her mistake.

Read more at; https://brainly.com/question/18630757

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