38) Equation

Bonds of 6, 7, 8, 9: Building

38.1 Equation Building


Develop the concept of related addition and subtraction equations, rearranged using the part-part-whole relationship, for two-part bonds of 6, 7, 8 and 9.

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, plus
  • subtraction, subtract, take away

Core Activity Support Materials

Click to open answers in a new tab.


A little easier

Equation building

The teacher models Activity 38 Equation Building  for Bonds of 6, linking the Bond Blocks, part-part-whole diagram and written equations. This is demonstrated for Bonds of 6 in the video at the top of this page. Leave the worked example on the activity board out for the student to use. The student uses this to complete the same activity for two-part Bonds of 7. 

Repeat this. The teacher models Activity 38 Equation Building for Bonds of 8. This is demonstrated in the video below. The student uses this worked example to complete the same activity for two-part bonds Bonds of 9.

A little harder

Atypical arrangement

Addition and subtraction equations don’t have to be written as 

Part + Part = Whole

Whole – Part = Part

An alternative arrangement is

Whole = Part + Part

Part = Whole – Part

38 Harder Atypical Arrangement Add
38 Harder Atypical Arrangement Sub

Read the Teacher Notes “Building Equations Using Part-Part-Whole” from page 8 onwards for more information about Atypical Arrangement using Part-Part-Whole


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

Activity 39

Bonds of 6, 7, 8, 9: Missing Number Equations, Tic-Tac-Toe