Here is one example of when you would use the friendly number strategy to subtract.
42 - 18
We will turn the 18 into a friendly number, which is going to be 20.
(42 + 2) - (18 + 3)
44 - 20
Now it is easier to subtract 44 - 20 than it is 42 -18. With 42 - 18 we would have to barrow whereas with 44 -20 we do not have to barrow and we can do it in our head easier and makes it faster.
The answer is 2 all you have to do is go to any point and do rise over run it rose 2 times and ran only once so it would be 2/1 which equals 2
Mean=average=sum of terms/number of terms...
(25+17+38+11+24)/5
115/5
23
12 out of 30 % because if you add 12+20+8= it equals 30 and they said there are 12 blueberry muffins.