Rounding isn't necessary. The distributive property tells you that 13 x 9 = 90 + 27 = 117
If you have to, you could estimate that 10 x 10 = 100
You do not need to estimate multiplication by 9. 13*9 = 117.
65 - 9 = 56
It is 5 + 4 = 9.
Their average is 22 and their difference is 9 so use 22 and 9 13*31 = 222 - 92 = 484 - 81 = 403
9 + 63 = 72 lbs.
Only if the digit in the place you're rounding to is a 9.
65 - 9 = 56
9X60
It is 5 + 4 = 9.
8/11 + 3/9 8/11 + 3/9
9+63+863+9
The estimated answer is 20.
Their average is 22 and their difference is 9 so use 22 and 9 13*31 = 222 - 92 = 484 - 81 = 403
If you are rounding to the 9 on the right, the number stays the way it is. If you are rounding to the 9 on the left, it rounds to 489000000
If you are rounding to the 9 on the right, the number stays the way it is. If you are rounding to the 9 on the left, it rounds to 489000000
9 + 63 = 72 lbs.
If you are rounding to the 9 on the right, the number stays the way it is. If you are rounding to the 9 on the left, it rounds to 489000000
If you are rounding to the 9 on the right, the number stays the way it is. If you are rounding to the 9 on the left, it rounds to 489000000