66 + 98 = 164.
Note: simple calculations like this one are easier to do with a calculator. If you don't have a calculator available, your computer probably has one for you to use (check under "Programs", "Applications", etc).
66 plus 66 equals 132
49 + 66 + 132 + 31 = 278
98 plus 65 equals 163.
66 + 99 = 165
It might be possible to work this in your head. Your 98 is 100 minus 2. This means 98 plus 98 is 100 plus 100 minus 2 minus 2. That's 200 minus 4 which gives 196 as the answer.
66 plus -62 = 4
It is equal to 66
2076
220
104
6y + 5y = -66 11y = -66 (-66/11 = y) y = -6
13 + 53 = 66
19 plus 79
35
66 times 6 equals 396.
It is 98*6 = 588
19 plus 79