31) Equation

Bonds of 10: Building

31.1 Equation Building


Develop the concept of related addition and subtraction equations, rearranged using the part-part-whole relationship, for two-part bonds of 10.

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 10: Equation Building a little easier activity board to scaffold building addition and subtraction equations for one bond of 10.

  • 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.

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

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 in addition and subtraction equations. Go to

Activity 32

Bonds of 10: Missing Number Equations, Fill a Row