Level 6- Mental Maths

Question 1

What number is five cubed?

Answer 1

125

Question 2

A circle has radius r.

What is the formula for the area of the circle?

Answer 2

Area = pi x radius x radius

Question 3

Multiply minus six by minus two.

Answer 3

12

Question 4

What is one third of three-quarters of one hundred?

Answer 4

1/3 of 75 = 75 ÷ 3 = 25

Question 5

I’m thinking of a number. I call it n. I square my number then add four.
Write an expression to show the result.

Answer 5

n2 + 4

Question 6

There are seven red and three blue balls in a bag. I am going to take a
ball out of the bag at random. What is the probability that the ball will
be blue?

Answer 6

Total number of balls = 7 + 3 = 10

Probability (blue ball) = 7 out of 10 = 7/10 = 0.7

Question 7

I am thinking of a number. I call it n.
I double my number then I subtract three. Write an
expression to show the result.

Answer 7

2n - 3

Question 8

What percentage of fifty pounds is thirty-five pounds?

Answer 8

70%

Question 9

On average, the driest place on earth gets only
nought point five millimetres of rain every year. In
total, how much rain would it expect to get in twenty
years?

Answer 9

10 mm

Question 10

What is three point nine divided by two?

Answer 10

1.95

Question 11

What is half of two-thirds?

Answer 11

1/3

Question 12

The population of the United Kingdom is about
fifty-nine million.
Write this number in figures.

Answer 12

59 000 000

Question 13

What is three-fifths of forty pounds?

Answer 13

One fifth (£40 ÷ 5) = £8
 Three fifths (£8 x 3) = £24

Question 14

I am thinking of a number. I call it
n. I add five to
my number.
Write an expression to show the result.

Answer 14

Answer: n + 5

Question 15

Five percent of a number is 8. What is the

number?

Answer 15

5% = 8
10% =16
100% = 160

Question 16

What is the remainder when you divide three

hundred by twenty-nine?

Answer 16

10 x 29 = 290 Therefore remainder is 10

300 – 290

Question 17

Twenty-five per cent of a number is seven.

What is the number?

Answer 17

25% = 7
50% = 14
Therefore 100% = 28

Question 18

The first even number is two.

What is the hundredth even number?

Answer 18

200

Question 19

The mean of two numbers is 8. One of the numbers is

two. What is the other number?

Answer 19

Mean = 8, Total of 2 numbers is 16 because 16 ÷ 2 = 8
If one of the numbers is 2 then the other number must be
14 (16 – 2)

Question 20

Multiply 8.7 by 2

Answer 20

8.7 x 2 = 17.4

Question 21

The first odd number is 1. What is the hundredth odd

number?

Answer 21

199

Question 22

Add four to minus five.

Answer 22

-1

Question 23

How many nought point fives are there in

ten?

Answer 23

10 ÷ 0.5 = 20

Question 24

What is the sum of the angles in a

rhombus?

Answer 24

360°

Question 25

Multiply minus eight by minus three.

Answer 25

-8 x -3 = 24