1245
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.)
0.008
166
41.5
498.8571
9.96
9.96
1245
498
0.0161
Well, isn't that a happy little question? To divide 498 by 7, you can start by seeing how many times 7 goes into 49 (which is 7), then multiply that by 10 to get 70. Subtract that from 49 to get 9, then bring down the 8 to make 98. 7 goes into 98 about 14 times, so 498 divided by 7 is 71.
7.5455
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.)
0.008
166
498 + k*504 where k is an integer.