9+90=99 (90 is ten times as much as 9)
Five
5600
555
-12
118
Five
6999999
2x3=6+4=10 2.
3a+10(a+4)=170
ten ones with an infinite number of zeroes.
5600
555
415
555
-8
To estimate the sum is to guess what the answer is for an addition problem. For example, if it was 8 + 9 you would see what number 8 is close to (like ten) and do the same with number nine and your estimate would be 20.
If ten times the number n decreased by 13 is equal to the square of the same number n increased by 3, then the value of n is either 8 or 2.