25
INDICES, STANDARD FORM
AND SURDS
The photo shows a male Escheria coli bacteria. You may have heard of e-coli. These bacteria
are commonly known in relation to food poisoning as they can cause serious illness. Each
bacterium is about a millionth of a metre long. That can be written as 0.000001m, or in
standard form as 1 × 10
m long. Standard form allows us to write both very large and
6
very small numbers in a more useful form.
Objectives
Before you start
In this chapter you will:
You need to be able to:
work out the value of an expression with zero,
use the index laws
negative or fractional indices
round numbers to one signifi cant fi gure.
convert between standard form and ordinary numbers
calculate with numbers in standard form
manipulate surds
make estimates to calculations using numbers in
standard form.
610