Partitioning An arithmetical strategy involving partitioning, or breaking up, a number into two parts without counting, e.g. partitioning 6 into 5 and 1.
Part-whole thinking The ability to conceive simultaneously of a whole and two parts, e.g. conceiving of 10 and also of the parts 6 and 4. This means children do not need to rely on counting-by-ones to add and subtract.
Developing partitioning as a strategy is essential for children to be able to solve problems efficiently using bigger numbers. Once children are securely and confidently counting on and back from the bigger number, then they are ready to develop part whole thinking. We can do this by providing lots of experiences for children to see that they can split up numbers into parts to solve problems. This clip from NZ Maths is a fantastic illustration of how ten frames can be used to help children see this for themselves.
It also shows how you can use the teaching model of first using materials, moving on to screening or imaging, then finally moving to using bare numbers, or number properties.
Look further on the Professional Development section of the NZ maths website for more great ideas of how to teach at each stage of learning in numeracy!