Adding on tens-by Harley

Learning-Intention:W.A.L.T-add tens to any number by counting in tens or adding ten together.
Success Criteria: I know I am successful when I can add tens together.

Problems:
1.40 carvings + 20 carvings =60 carvings
I know that it's 60 because 4 tens + 2 tens =6 tens. 
2.37 bananas + 40 bananas =77
I know it's 77 because 40 bananas + 30 bananas =70 bananas +7 =77.
3.15+5+10=30
I know it's 30 because 15+5=20+10=30.