74-17= 57 because if you subtract 10 from 74, it would be 64, then you need to subtract 7 from 64, which gives you 57.
9+7=16 because 10+7 would be 17, but since 9 is one less than 10, you need to subtract one from 17, which gives you 16.
17+(-30)=(-13) because adding 17 to -30 only brings up -30 to -13, and -30<-13.
-41+24=-17. Same reason as question 3, only different numbers.
-36+(-7)=-43 because adding two negatives together is like subtracting two positives from each other.
14+64=78 because adding 10 to 64 is 74 and 74+4=78.
-53-42=-95 because when you subtract a positive from a negative, it decreases the number even more.
-17-(-62)=45 because -62 is less than -17 and it is being subtracted from -17 so the answer becomes positive.
Hope this helps :)
