How_To_Be_Good_At_Math

NUMBERS • SEQUENCES AND PATTERNS 15

1, 2, 3, 4, 5, 6,

RULE: ADD 1

...

RULE: MULTIPLY BY TEN

RULE: ADD ONE, THEN MULTIPLY BY TWO

+1 ×2 +1 ×2 +

8, 9, 18, 19, 38, 39, ...

1, 10, 100, 1000, 10 000, ...

Spot the sequence

Can you work out the next two terms in

each of these sequences? You’ll have to

work out the rule for each sequence

first – a number line might help you.

TRY IT OUT

22, 31, 40, 49, 58, ...

4, 8, 12, 16, 20, ...

100, 98, 96, 94, ...

90, 75, 60, 45, 30, ...

Simple sequences

There are lots of ways to make sequences. For example, they

can be based on adding, subtracting, multiplying, or dividing.

Each term is multiplied

by 10 to get the next

term in this sequence.

In this sequence, we add

one to each term to get

the next term.

Sometimes, a rule can have

more than one part. In this

sequence, we add one, then

multiply by two, then go back

to adding one, and so on.

The dots show that

the sequence continues

7

Answers on page 319

4TH TERM 5TH TERM

The fifth term in the

sequence will be 7 + 2

+1 +1 +1 +1 +

×10 ×10 ×10 ×

?

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