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.

Missing Numbers focuses 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.

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. 5+6=?

= Show Me =
Move the objects to show partitioning in subtraction e.g. 5-2=?

= Addition =
There are 6 altogether. How many are (hiding) in my hand? e.g. ?+3=6

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