Whole Numbers (Integers)

Natural Numbers are the numbers that we use to count:  1, 2, 3, 4, 5, 6, 7, …
We represent all of them by
= {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, …}

When we add number zero and the negative numbers to the Natural Numbers, we obtain the Whole Numbers and we represent all of them by:
= {…, -4, -3, -2, -1, 0, 1, 2, 3, …}
and we represent these numbers in a straight line




The absolute value of a whole number is the natural number which results when we remove its sign:
|-5| = 5                |11| = 11                    |0| = 0

Remember the hierarchy of operations:
- Brackets first.
- Powers and roots.
- Multiplication and division.
- Addition and subtraction.

Exercise.- Calculate:

a) 7 - 5·(3-4)+ 8:2 = 

b) 3- [4 - 5·3 + 12:2 - (4 + 5·3)] =

c) 3·5 - 4 + 2·(5- 3·2) + 8:(4-2) =

  d) |-7|= 

  e) |13|=

Solutions: a) 16; b) 27; c) 13; d) 7; e) 13