# How to subtract numbers

## How can "subtract" with simple methods:

By the end of this week, everyone will be able to calculate how many school days left...
Basic Subtraction Math Lesson - Learn to Subtract

1. Partitioning

This involves splitting one quantity into two or more sub-quantities. This is the inverse of the â€˜Combiningâ€™ model for addition.
Some examples of this are:

typical word problem for this kind of subtraction is:

â€œIn a box are 5 cars. Two are Johnâ€™s and the rest are Tomâ€™s. How many are Tom's?

2. Reduction

This type of subtraction involves reducing the value of one quantity. This subtraction structure is often known as â€˜take awayâ€™. It should be evident from this that â€˜take awayâ€™ is not an appropriate description for other types of subtraction and therefore the commonly-held view that â€˜subtractionâ€™ and â€˜take awayâ€™ are interchangeable terms with the same meaning is mistaken. This is a common misconception among children who may have been incorrectly taught or who have rarely encountered any other form of subtraction. The â€˜reductionâ€™ form of subtraction is the inverse of the â€˜augmentationâ€™ model for addition.