66 plus 98 equals 164. This is because addition is a basic arithmetic operation where two numbers are combined to find their total sum. In this case, when you add 66 and 98 together, you get 164 as the result.
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).