Adding and Subtracting Decimal Numbers with Model

Which equation matches the model?

• 0.73 - 0.23 = 0.50

• 0.50 + 0.23 = 0.73

• 0.73 + 0.23 = 0.50

• 0.73 - 0.50 = 0.23

What equation matches this model?

• 0.32 + 0.17 = 0.49

• 0.32 - 0.17 = 0.49

• 0.49 - 0.17 = 0.32

• 0.49 + 0.17 = 0.32

Which decimal represents the amount shaded on the models?  

• 183

• 1.83

• 1.083

• 0.83

• 11.27

• 22.37

Which student correctly solved their math problem?

​ (a)   ​

• Both

• Neither

• Gayle

• Ian

Which problem is represented by this model? BE CAREFUL!

• 0.27 - 0.9

• 0.18 + 0.09

• 0.9 + 0.18

• 0.27 - 0.09

-12.4 + 9.2 + 1 

Mathematical Equivalence

ON

What equation matches this model?

• 0.7 - 0.44 = 1.14 

• 1.14 - 0.44 = 0.7

• 1.14 + 0.7 = 0.44

• 0.7 + 0.44 = 1.14

Which student correctly solved their math problem?

• Both

• Neither

• Gayle

• Ian

Which problem is represented in the model?

• 0.32 - 0.17

• 0.49 - 0.32

• 0.32 + 0.17

• 0.49 - 0.17