7th Grade Section
WME@Kimpton Middle

More Fraction Addition

Think FractionsLet's consider adding fractions again. Try this experiment.

  1. A rectangle has been divided into 6 equal parts (their areas are equal) in a 3 × 5 grid. If you are unfamiliar with this type of grid, click in the grid and see what happens.

     

    Observe how the red, green, and blue fractions change when you make clicks.

  2. With mouse clicks, make one column blue. And the blue area is 3/15 of the whole rectangle. Can you think of another fraction that would represent the blue column? Explain your thinking below.

    Now make the next column red. What is the sum of the blue fraction and red fraction?

      3  
    15
    		  +  
      3  
    15
    		  =  
            
    15

  3. Is the following true or false?

      3  
    15
    		  +  
      3  
    15
    		  =  
      1      
    5    

  4. Make one row with two red and three blue cells, and the other rows green. Use this to help you visualize and answer this question.

      2  
    15
    		  +  
      3  
    15
    		  =  
            
    15

  5. Is this true or false?

      3  
    15
    		  +  
      2  
    15
    		  =  
      1      
    5