Number Bonds
Josh had 9 slices of cake in the fridge. He had 2 slices. After the party all the cake was gone! How many slices of cake did his guests have?
2+7=9 The guests had 7 slices of cake.
Charlie says you can use an addition problem to solve a subtraction problem. He says to solve 3-2=__ just add 3+2. How is Charlie right? How is he wrong?
3+2=5 3-2=1 this is wrong But addition problems do help solve subtraction problems in the same fact family. 2+1=3 helps to solve 3-2=1