The subtraction or subtraction is an operation of arithmetic that is represented by the sign (-) represents the operation of removing objects from a collection. For example, when there are 5 – 2 apples, it means 5 apples with 2 sacks, making a total of 3 apples. Therefore, 5 – 2 = 3. In addition to counting fruits, subtraction can also represent combination of other physical and abstract quantities using different types of objects: negative numbers , fractions , irrational numbers, vectors , decimals, functions, matrices, and more.
The subtraction follows several important patterns. It is anticommutative , which means that changing the order changes the sign of the answer. It is not associative, which means that when more than two numbers are subtracted, it matters in the order in which the subtraction is made. Subtracting 0 does not change a number. Subtraction also obeys predictable rules regarding related operations, such as addition and multiplication . All of these rules can be tested by subtracting whole numbers and generalizing them by real numbers and beyond. The general binary operations that follow these patterns are studied in abstract algebra .
Subtracting is one of the simplest number tasks. Subtraction of very small numbers is accessible to young children. In elementary education , students are taught to subtract numbers in the decimal system, starting with a single digit and progressively addressing more difficult problems. Mechanical aids range from the ancient abacus to the modern computer .
