Question

Please help

Sandra used partial products to find the product of 438 x 17 by multiplying 438 by 1 and 438 by 7 to get 3,066.Is Sandra correct? Compare your answer to Sandra's and explain why it is or is not the same.

Answer 1

No, Sandra is not correct.

Explanation:

Sandra was needed to multiply 438 by 17.

`438*17 = 438*(10 + 7) = 438*10 + 438*7 = 4380 + 3066 = 7446`.

17 = 10 + 7.

Sandra multiplied 438 by 1 and then multiplied 438 by 7. Sandra had taken
`438*7 = 3066` as the answer.

Multiplying by 1 and multiplying by 10 is not same.

Sandra mistakenly multiplied 438 by 1 instead of 10.

Hence, Sandra got the wrong answer.