$0.59/sprint
Add within 20 without crossing 10
Add mult of 10 to mult of 10 within 100
Add multiples of 10 within 100
Add within 100 without crossing the 10
Add 2-digit numbers without renaming
Add 2-digit #s without renaming (2)
Add within 200 without renaming
Add multiples of 10 to 2-digit #s
Add multiples of 10 within 200
Add 10 & 100 to a 3-digit number
Add multiples of 100 within 1,000
Add 3-digit numbers without renaming