Question

What is the student error in the multiplication below?

Multiply the ones: 957 times 23 = 2871. Above the 9 in 957 is 1, above the 5 in 957 is 2.



Multiply the tens: 957 times 23 = 2871. 2871 + 1914 = blank. Above the 9 in 957 is 1, above the 5 in 957 is 1.

Answer 1

Answer: 1) When multiplying the ones, the student did not carry over a ten to the next place in the first multiplication.

2) When multiplying the ones, the student should have calculated 3 times 2 plus 5 as 11 and placed a 1 in the tens place.

3) When multiplying the tens, the student did not use the 0 place holder for the ones place.

4) When multiplying the tens, the student should have calculated 2 times 1 plus 9 as 11 and used a 1 should in the hundreds place.

Answer:

The correct option is;

4) When multiplying the tens, the student did not use the 0 place holder for the ones place

Explanation:

Here we have when doing long multiplication, the student correctly multiplies the ones as 2871, however, before commencing multiplication of the tens, a 0 should be placed in the ones place of the result as a place holder such that the outcome of the multiplication of the tens should be;

19140

Hence, the correct result should be 2871 + 19140 = 22011

The correct option is therefore, that "When multiplying the tens, the student did not use the 0 place holder for the ones place."

Explanation:

Answer 2

When multiplying the tens, the student didn't use the 0 place holder for the ones place.

Explanation:

When using or doing long multiplication the answer was correct (2871) BUT before multiplying the tens, a zero should be placed in the ones place of the results. So, the tens should be 19140

2871+19140=22011