
Rewrite your subtraction problem as addition (keep, change, change) and solve.
Rewrite your subtraction problem as addition (keep, change, change) and solve.
Rewrite your subtraction problem as addition (keep, change, change) and solve.
Rewrite your subtraction problem as addition (keep, change, change) and solve.
Rewrite your subtraction problem as addition (keep, change, change) and solve.
Rewrite your subtraction problem as addition (keep, change, change) and solve.
Rewrite your subtraction problem as addition (keep, change, change) and solve.
Rewrite your subtraction problem as addition (keep, change, change) and solve.
Earn extra credit points for finding the sum of #1-#9.
Earn extra credit points for finding the sum of #10-#18.
Earn extra credit points for finding the sum of #19-#27.
Earn extra credit points for finding the sum of #28-#36.