Exponents and surds

6

Contents:

A Exponent or index notation [1.4, 1.9]

B Exponent or index laws [1.9, 2.4]

C Zero and negative indices [1.9, 2.4]

D Standard form [1.9]

E Surds [1.10]

F Properties of surds [1.10]

G Multiplication of surds [1.10]

H Division by surds [1.10]

Opening problem

#endboxedheading

Amadeo Avogadro ( 1776 - 1856 ) established that one gram of

hydrogen contains 6 : 02 £ 1023 atoms.

Things to think about:

² How can we write this number as an ordinary number?

² How many atoms would be in one tonne of hydrogen gas?

² Can you find the mass of 1030 atoms of hydrogen?

We have seen previously that 2 £ 2 £ 2 £ 2 £ 2 , can be written as 25.

25 reads “two to the power of five” or “two with index five”.

In this case 2 is thebaseand 5 is theexponent,powerorindex.

We say that 25 is written inexponentorindex notation.

A EXPONENT OR INDEX NOTATION [1.4, 1.9]

2

5

exponent,

poweror

index

base

The use of also called or , allows us to write products of factors and also to

write very large or very small numbers quickly.

exponents, powers indices

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Y:\HAESE\IGCSE01\IG01_06\123IGCSE01_06.CDR Friday, 14 November 2008 10:52:42 AM PETER