Most people memorize the addition of all the single-digit numerals.
Or, you can count on your fingers and toes.
Or, you can add half of 8 to 9 (4), getting 13, then add the other half of 8 to 13, getting 17.
11 + 11 + 11 + 10 + 9 + 9 + 9 + 8 + 8 + 8 + 8 + 8 + 8 + 7 + 2 = 127
To find 2 plus 8, I use the strategy of counting up from the first number. Starting at 2, I count up by adding 8: 3, 4, 5, 6, 7, 8, 9, 10. Alternatively, I can simply recall that 2 plus 8 equals 10 from basic addition knowledge. Thus, the answer is 10.
89
True. 9 + 8 + 1= 18 and 9 + 1 + 8 =18.
9 + 6 + 9 + 6 + 9 + 8 + 5 + 2 + 9 + 8 + 7 + 6 + 5 + 4 + 3 + 2 + 1 = 99
true
Tautology?
9 + -15 + 8 = 2
9 + 4 + 7 + 8 = 28
If there is an equals sign after the first 8, the answer is yes.
It's a magnificent example of pure nonsense.
6 + 9 + 8 = 23