WHY? Do it this way: 1+100=101, and there are 50 of these groups. Multiply 101 by 50 and you get 5050
2)The pet store donated 21 dog bones to the community shelter. A dog came along and started eating bones, eating one bone per two minutes each. Just as the first dog finished his second bone, another dog came along and started eating the bones at the same rate. Then another dog came along and started eating bones at the same rate. How long did the dogs take to finish their part of the meal?
1st Dog: O O
2nd Dog: O O
3rd Dog: O O
1st Dog: O O O
2nd Dog: O O O
3rd Dog: O O O
We can infer that going through 1 bone ahead of each other until 21 bones are finished, each dog would take 7 bones, which would require 14 minutes for each dog, thus requiring 42 minutes to finish.