Question

Tanya needs to write the number twenty-one and twelve thousandths as adecimal on her science lab report. How should she write this in standard form?A12.012B21.121c21.12D21.012

Answer 1

We have the number: twenty-one and twelve thousandths.

We have that twenty-one is simply 21.

However, we need to represent twelve-thousandths having into account that we need to divide that number by 1000 (we have thousandths), that is:

$\frac{12}{1000}=0.012$

Then, the number, in standard form, is:

21 + 0.012 = 21.012

Therefore, the number is 21.012 (in standard form, three decimals.) (option D)