ABSTRACT
Whole numbers are simply the numbers 0, 1, 2, 3, 4, 5 . . . (and so on). Integers are like whole numbers, but they also include negative numbers. +3,+5 and +72 are examples of positive integers; −13,−6 and −51 are examples of negative integers. Between positive and negative integers is the number 0, which is neither positive nor negative. The four basic arithmetic operators are add (+), subtract (−), multiply (×) and divide (÷). It is assumed that adding, subtracting, multiplying and dividing reasonably small numbers can be achieved without a calculator. However, if revision of this area
is needed then some worked problems are included in the following sections. When unlike signs occur together in a calculation, the overall sign is negative. For example,
5+ (−2) = 5+−2 = 5− 2 = 3 3+ (−4) = 3+−4 = 3− 4 = −1
and (+5)× (−2) = −10
Like signs together give an overall positive sign. For example,
3− (−4) = 3−−4 = 3+ 4 = 7 and
You can probably already add two or more numbers together and subtract one number from another. However, if you need a revision then the following worked problems should be helpful.
