Addition and subtraction - Vocabulary

Addition is a fundamental mathematical operation where two or more numbers are combined to find their total. In contrast, subtraction is the process of determining the difference between numbers by reducing one number by another. The concept of 'equals' signifies that the amounts on either side of the equals symbol are the same. For example, '500 + 100 = 600' and '500 – 100 = 400' illustrate that the sum and the difference respectively result in values that are equal to the calculations on the other side of the equals symbol. This principle is further exemplified through the equations '600 = 100 + 500' and '400 = 500 – 100', demonstrating the equality between different expressions.

Column addition and column subtraction are efficient methods for performing calculations with larger numbers, where the numbers are aligned beneath each other to facilitate easy computation. Multiples of 100 and multiples of 10 are the products obtained when 100 or 10 is multiplied by whole numbers, such as '100 x 3 = 300' and '10 x 3 = 30'. An efficient approach to addition might involve using known facts to quickly add numbers without resorting to column addition. Various methods, including mental partitioning and using equipment, can be employed to solve calculations. The vocabulary associated with addition and subtraction also includes terms like 'exchange', where values are swapped for equivalent amounts in different denominations, 'estimate', which involves making a reasonable guess close to the correct answer, and 'near numbers', which are numbers close to a round figure that can simplify estimations. The inverse operation reverses the effect of another, such as using subtraction to check the result of addition. Inequality symbols are used to compare numbers, indicating whether one number is less than, equal to, or greater than another.