12) Equation

Bonds of 5: Building 


Develop the concept of related addition and subtraction equations, rearranged using the part-part-whole relationship, for two-part bonds of 5.

Click this link to read Teacher Notes for more information about “Building Equations Using Part-Part-Whole”.


  • part-part-whole: where the two parts are a bond of the whole number.
  • equals, is equal to
  • addition, add
  • subtraction, subtract, take away

Core Activity Support Materials

Click to open answers in a new tab.


A little easier

Equation building

Use Bonds of 5: Equation Building a little easier activity board to scaffold building addition and subtraction equations for one bond of 5.

  • Arrange each block, in the correct positions, on the rectangles of the first equation.
  • Record these numbers using a dry erase marker.
  • Repeat for each equation.

At the end of the activity discuss:

  • The different position of the whole in addition equations compared to subtraction. 
  • How the blocks representing the parts swap positions with each other. The block representing the whole stays in the same position for each addition equation and each subtraction equation.


Apply the concept of building related addition and subtraction equations, using part-part-whole, to find missing parts in addition and subtraction equations. Go to

Activity 13

Bonds of 5: Missing Number Equations, Fill a Row