Three essential ingredients of mathematics learning are knowledge, skills and understanding. Knowledge concerns the factual information that is necessary to do mathematics (e.g. the meaning of ‘5’). Skills provide us with the opportunity to use our knowledge (e.g. being able to add two numbers). Understanding is demonstrated when we know why and how to use and apply our knowledge and skills (e.g. to add the number of children in all the groups to find the total number of pencils which are needed).