Missing Numbers

Missing Numbers introduces problem solving skills to young students. Problem solving can and should be introduced at this early stage, so that young students can begin to demonstrate mathematical 'talk', through discussion of different ways to solve problems and metacognition.

Once students have reached the milestones of regularly and consistently counting backwards and forwards to ten or twenty, basic addition and subtraction can be introduced utilising familiar, everyday objects. It is important to make sure that these types of activities are genuine and experiences should be encouraged, rather than lists of sums.

Missing Numbers continues on from this, focusing on problems involving addition and subtraction. Initially students solve problems through counting all the objects visible or through partitioning or segregation and counting all the objects given. Missing Numbers encourages students to use more sophisticated strategies such as counting backward and counting on.

Don't understand what I'm trying to say? Take the equation 5 + 4 = ?

  • Count all - Students count all the objects present, starting from 0. ie, they count 1, 2, 3, 4, 5, 6, 7, 8, 9
  • Count on - Students recognise a collection or have counted it previously, then count on from this. e.g. 5, 6, 7, 8, 9
  • Near Double, or doubles fact - Students recognise that 5 + 4 is could be 4 + 4 + 1 or 5 + 5 - 1
  • Known fact - Students recall known addition facts.
  • Count back - Appropriate for subtraction problems e.g 5 - 2 = students would count backwards from five, four three.

Missing Numbers scaffolds students through the use of seen and unseen (hidden) objects, allowing students to 'check' their answer by 'peeking' at the hidden objects and the ability to move objects to allow ease of counting.


Missing Numbers is broken into four different types of activities:

How Many

How many altogether
e.g. 3 + 5 = ?

Show Me

Move the objects to show partitioning in subtraction
e.g. 10 - 7 = ?


There are 11 altogether.
How many are (hiding) in my hand? e.g. 7 + ? = 11


There are 4 altogether.
How many are in the box? e.g. 4 - ? = 1

Teacher Tool

Use the Teacher Tool to create your own equations or problems. Alternatively you might like to come up with an answer and have students think of the problem. Once done you can either save your screen to the photo gallery or email the screen shot. This is useful for portfolios and record keeping.

Compatible with iPhone and iPad. Requires iOS 4.3 or later.
16.4 MB