Question

Explain the mistake
3.5 times by 10 = 3.50

Answer 1

3.5 × 10 = 35.0
The mistake is that you only added a zero to the answer (3.5 -> 3.50), but you forgot to replace the point in your answer (because 3.50 is wrong and 35.0 is correct). Hence, you should have replaced to point, by moving it one spot to the right.