1 Understanding Number
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Understanding Number Learning Objectives
(Syllabus sections 1, 3, 4, 6, 7, 8)
In this chapter you will learn to: • Identify and use different types of number • Express numbers as products of prime numbers • Find the lowest common multiple and highest common factor of two or more numbers
• • • • •
Understand operations and inverses Recognise common mathematical symbols Understand and order integers Convert numbers to and from Standard Form Use the recognized order of working in calculations
Introduction By the end of this chapter, you should know more about the different types of numbers that you need to study for the rest of the course. You may feel that you know most of it already, but please work through it as there are plenty of things in it that will help you gain valuable marks in your examination. Treat it as revision if you like.
Essential Skills
NO CALCULATOR IN THIS EXERCISE
To get the most from this course, you should know the multiplication tables from 2 to 10 and be able to recall them without hesitation. It is also important to know the facts about addition and subtraction. Try the following mini-test and see how quickly you can answer the questions without using a calculator. a 4 × 6
b 3 × 7
c 8 × 5
d 9 × 8
e 2 × 7
f 6 × 9
g 8 × 8
h 9 × 5
i 7 × 7
j 3 × 6
k 6 + 7
l 5 + 8
m 9 + 7
n 3 + 5 + 9
o 8 + 9
p 11 + 9
q 13 + 6
r 3 + 4 + 5
s 16 + 5
t 4 + 17
u 9 – 4
v 11 – 7
w 15 – 9
x 7 − 4
y 16 ÷ 8
z 24 ÷ 6
Time: Here is a rough guide, just for you, so that you can get an idea of how much you might need to practise. • 1 minute, 25 correct Excellent! • 3 minutes, 20 correct Very good! • 5 minutes, 18 correct Not bad! • More than 5 minutes Keep practising!
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