Great answers already by Bjoern and Simon^

I’ll add a little trick to make these easier when working mentally. I’d first do the main work of the calculation (e.g. 37 ÷ 8) and afterwards put the decimal in the right place.

So 37 ÷ 8 = 4 rem 5 = 4 5/8 = 4.625

Then I’d say okay fine, 37 ÷ 80 must be 46.25%, same as 37,000 ÷ 80,000. Then we need to divide by 1000 and the final answer will be 0.04625%

Alternatively you could estimate like Bjoern did, and then calculate the 37 ÷ 8 at the end to figure out the exact digits for the “about 0.05%” …since they wre “4625” the answer must be 0.04625%

The main takeaway here is that you can do two types of low-intensity calculation (the rough estimate fiddling with the zeros, and the exact division disregarding the zeros) and easily put them together into the correct answer.