7th Grade Section
WME@Kimpton Middle

Fraction Subtraction

Think FractionsAt this point, you have already learned about adding fractions. With that knowledge, fraction subtraction is really simple.

You may remember from whole numbers, subtraction is the inverse operation of addition. In addition, you increase a number. In subtraction you decrease a number. If you add the amount you decrease back, you get the original number.

  1. A rectangle has been divided into 6 equal parts (their areas are equal) in a 2 × 3 grid. Try clicking in the grid and see what happens.

     

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

  2. First, make four cells blue, the rest green. The blue area is 4/6 of the whole rectangle.

    Now make one blue cell red. What does this tell you about:

      4  
    6
    		  −  
      1  
    6
    		  =  
            
    6

  3. Look at the blue area. Is it 1/2 of the whole or not? Why? So true or false:

      4  
    6
    		  −  
      1  
    6
    		  =  
      1      
    2    

  4. Make another blue cell red cell. Use this to help you visualize and answer:

      4  
    6
    		  −  
      2  
    6
    		  =  
            
    6

  5. Look at the area 2/6 represents. Is it 1/3 of the whole or not? Why? So true or false:

      4  
    6
    		  −  
      2  
    6
    		  =  
      1      
    3