The instructions are to Round each number to the greatest place. The add.
21+34=
ok you have 21+34? Ok then round your places. Remember that anything above the 5th number is going to be the next highest number. Say if you had 86 (since that's higher than 85) then you would round it to 90. So 21 is closest to 20 and 34 is closest to 30. Therefore you have, 20+30 which is 50!
Glad to help,
brad