 11, 22, 33, 44, etc. This number sequence is increasing by 11.

# Number Sequences (Easy)

A number sequence is a series of numbers written in such a way that each number in the sequence can be got by following a given rule. For example, in the sequence 4, 16, 64, 256, ... each number in the sequence can be got from the previous term by multiplying by 4. In this case, the rule is: multiply by 4. The numbers in a sequence are called 'terms': in 4, 8, 12, 16, ... '4' is the first term and '12' is the third term.

See how you do in this 11-plus Maths quiz with these slightly more difficult sequences. Make sure you've played our first set of 'very easy' quizzes on number sequences before tackling this one.

1.
Find the missing term.
1, 4, 9, 16, X, 36, 49, ...
25
23
24
32
The terms of this sequence are the counting numbers squared: 12 = 1; 22 = 4; 32 = 9; 42 = 16; 52 = 25 and so on
2.
Find the missing term.
-16, -11, -6, -1, X, ...
4
-4
-5
5
The next term is got from the previous term by adding 5, e.g. -11 + 5 = -6 and so on
3.
Find the missing term.
11, 22, 33, 44, X, ...
88
77
66
55
The next term is got from the previous term by adding 11, e.g. 22 + 11 = 33 and so on
4.
Find the missing term.
13, 29, X, 61, ...
35
45
55
33
The next term is got from the previous term by adding 16, e.g. 13 + 16 = 29 and so on
5.
Find the missing term.
5, -5, -15, X, ...
-25
15
-10
-30
The next term is got from the previous term by subtracting 10, e.g. 5 - 10 = -5 and so on
6.
Find the missing term.
5, 25, 125, X, ...
150
425
625
525
The next term is got from the previous term by multiplying by 5, e.g. 25 × 5 = 125 and so on
7.
Find the missing term.
½, ¼, ⅛, X, ...
112
110
116
132
The next term is got from the previous term by multiplying by ½, e.g. ¼ × ½ = ⅛ and so on
8.
Find the missing term.
64, 16, 4, 1, X, ...
½
¼
¾
The next term is got from the previous term by dividing by 4, e.g. 64 ÷ 4 = 16 and so on. Use your calculator
9.
Find the missing term.
4, 9, 14, X, ...
19
20
18
17
The next term is got from the previous term by adding 5, e.g. 9 + 5 = 14 and so on
10.
Find the missing term.
60, 15, 3.75, X, ...
0.625
0.25
0.125
0.9375
The next term is got from the previous term by dividing by 4, e.g. 60 ÷ 4 = 15 and so on. Use your calculator
Author:  Frank Evans