This question is a simple one. To answer this question, you need to understand the description in the question and determine to multiply or divide the number.
The first problem would be:
50.75 x 0.18= 9.135
If you need to estimate, 50.75 is near 50; 0.18 is near 0.2 or 1/5 so it would be: 50/0.2= 10
The second problem would be:
196 / 0.499: 392.785
If you need to estimate, 0.499 is near 0.5 then 196/0.5 would be 392