Maths Definitions Flashcards
(25 cards)
What is a prime number?
A number with only 1 and itself as factors.
What is the index form of a number?
A number written in powers e.g. 24=2 (to the power of 3) x 3
What is a factor?
A number which divides exactly into another number e.g. 8 is a factor of 40
What is a product?
The number obtained by multiplying two or more numbers together.
What is a prime factor?
A factor which is also prime e.g. 2 is a prime factor of 24
What is the Highest Common Factor (HCF)?
The highest factor shared by two or more numbers. e.g. the hcf of 24 and 40 is 8
What is the Lowest Common Multiple (LCM)?
The lowest multiple shared by two or more numbers e.g. the lcm of 5 and 6 is 30
What does BIDMAS stand for?
Brackets, Indicies, Division, Multiplication, Addition, Subtraction.
What is the reciprocal?
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
How do you find the reciprocal of a fraction?
Flip its numerator and denominator e.g. the reciproal of 7/8 is 8/7 or 1 1/8
What do you need to do to add or subtract fractions?
Make them have the same denominator e.g. 1/2 + 1/6 = 3/6 + 1/6 = 4/6 = 2/3
How do you multiply fractions?
Just multiply the numerators and denominators e.g. 2/3 x 3/5 = 6/15 = 2/5
How do you divide fractions?
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
What is the product rule for counting?
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
What is the cube root of 8?
2 as 2x2x2=8
What is the fourth root of 81
3 as 3x3x3x3=81
How do you multiply and divide powers?
4 tpo2 x 4tpo3 = 4 tpo2+3 = 4 tpo5
5 tpo7 / 5 tpo3 = 5 tpo 7-3 = 5 tpo4
How do you raise powers to each other?
(3 tpo2)tpo4 = 3 tpo2x4 = 3 tpo 8
What is the result of a non-zero number being raised to the power of 0
= 1
What does it mean when something is written in standard form?
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
How do you multiply/divide in standard form?
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
How do you add/subtract standard form numbers?
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
What is a surd?
A root that can’t be simplified any further. They are irrational.
e.g. sqroot 2, sqroot 3, sqroot 5
Hw do you rationalise a fraction that has a surd as the denominator?
Multiply the numerator and denominator by the surd
e.g. 2/sqroot3 = sqroot3/sqroot3 x 2/sqroot3 = 2sqroot3/3
