Let's see. Estimating would start with rounding up 498. 498 will turn into 500. Next, we round 12. Twelve rounds to 10, so it ends up to become 500 divided by 10. 500 divided by 10 is 50. So, estimated, 498 divided by 12 would be somewhere near 50.
(by the way, 498 divided by 12 is actually, non-estimated, 41.5.)
41.5
12
332
12000
0.082
228 is a multiple of 12 so estimation is not necessary but if you must, then 240/12 = 20
5 over 12 (5/12) is the same as 5 divided by 12: 5 ÷ 12 = 0.4167
35.7=36 11.4=12 36 divided by 12 = 3 The answer is 3.
11.92
40000
1
The answer is 3. 36 divided by 12 = 3