Maths Definitions

Question 1

What is a prime number?

Answer 1

A number with only 1 and itself as factors.

Question 2

What is the index form of a number?

Answer 2

A number written in powers e.g. 24=2 (to the power of 3) x 3

Question 3

What is a factor?

Answer 3

A number which divides exactly into another number e.g. 8 is a factor of 40

Question 4

What is a product?

Answer 4

The number obtained by multiplying two or more numbers together.

Question 5

What is a prime factor?

Answer 5

A factor which is also prime e.g. 2 is a prime factor of 24

Question 6

What is the Highest Common Factor (HCF)?

Answer 6

The highest factor shared by two or more numbers. e.g. the hcf of 24 and 40 is 8

Question 7

What is the Lowest Common Multiple (LCM)?

Answer 7

The lowest multiple shared by two or more numbers e.g. the lcm of 5 and 6 is 30

Question 8

What does BIDMAS stand for?

Answer 8

Brackets, Indicies, Division, Multiplication, Addition, Subtraction.

Question 9

What is the reciprocal?

Answer 9

The quantity obtained by dividing 1 by a given number e.g. the reciprocal of n is 1/n, or the reciprocal of 5 is 1/5

Question 10

How do you find the reciprocal of a fraction?

Answer 10

Flip its numerator and denominator e.g. the reciproal of 7/8 is 8/7 or 1 1/8

Question 11

What do you need to do to add or subtract fractions?

Answer 11

Make them have the same denominator e.g. 1/2 + 1/6 = 3/6 + 1/6 = 4/6 = 2/3

Question 12

How do you multiply fractions?

Answer 12

Just multiply the numerators and denominators e.g. 2/3 x 3/5 = 6/15 = 2/5

Question 13

How do you divide fractions?

Answer 13

Find the reciprocal of the second fraction and multiply instead. e.g. 2/3 divided by 4/5 = 2/3 x 5/4 = 10/12 = 5/6

Question 14

What is the product rule for counting?

Answer 14

In order to find the total number of combinations in a given scenario, multiply the total number of options e.g. 5 shirts x 7 trousers x 4 jackets = 140 possible outfit combinations

Question 15

What is the cube root of 8?

Answer 15

2 as 2x2x2=8

Question 16

What is the fourth root of 81

Answer 16

3 as 3x3x3x3=81

Question 17

How do you multiply and divide powers?

Answer 17

4 tpo2 x 4tpo3 = 4 tpo2+3 = 4 tpo5

5 tpo7 / 5 tpo3 = 5 tpo 7-3 = 5 tpo4

Question 18

How do you raise powers to each other?

Answer 18

(3 tpo2)tpo4 = 3 tpo2x4 = 3 tpo 8

Question 19

What is the result of a non-zero number being raised to the power of 0

Answer 19

= 1

Question 20

What does it mean when something is written in standard form?

Answer 20

A x 10 tpo n, a way to write very large or small numbers

e. g. 4.3 x 10 tpo7 = 43,000,000
6. 83 x 10 tpo -4 = 0.000683

Question 21

How do you multiply/divide in standard form?

Answer 21

Deal with the powers separately

e.g. (4 x 10tpo6) x (8 x 10tpo-3) = (4x8) x (10tpo 6+-3) = 32 x 10 tpo 3 = 3.2 x 10 tpo4

Question 22

How do you add/subtract standard form numbers?

Answer 22

Transfer them into their full forms, calculate, then change them back into standard form

e.g. 5.1 x 10tpo5 + 2.4 x 10tpo4 = 510000 + 24000 = 534000 = 5.34 x 10tpo5

Question 23

What is a surd?

Answer 23

A root that can’t be simplified any further. They are irrational.

e.g. sqroot 2, sqroot 3, sqroot 5

Question 24

Hw do you rationalise a fraction that has a surd as the denominator?

Answer 24

Multiply the numerator and denominator by the surd

e.g. 2/sqroot3 = sqroot3/sqroot3 x 2/sqroot3 = 2sqroot3/3

Question 25

How do you simplify a surd?

Answer 25

Find a square number factor

e.g. sqroot 12 = sqroot4xsqroot3 = 2sqroot3