2.NBT.8

Mentally add 10 or 100 to a given number 100-900, and mentally subtract 10 or 100 from a given number 100-900.

1.		10 less, 10 more than 490
2.		100 less, 100 more than 873
3.		Which number is 10 more than 989?
4.		Which number is 10 less than 724?
5.		Which number is 100 more than 456?
6.		Which number is 100 less than 388?
7.		10 less, 10 more than 150
8.		10 less, 10 more than 183
9.		10 less, 10 more than 418
10.		10 less, 10 more than 106
11.		10 less, 10 more than 204
12.		100 less, 100 more than 403
13.		10 less, 10 more than 150
14.		10 less, 10 more than 290
15.		10 less, 10 more than 500
16.		10 less, 10 more than 620
17.		10 less, 10 more than 880
18.		Which number is 10 less than 100?