Flashcards in Section 1: Number Deck (29)

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1

## Integer meaning

### Another name for a whole number- either a positive or negative number, or zero

2

## What are 3 different forms of Rational numbers

###
1. Integers

2. Fractions

3. Terminating or recurring decimals

3

## What are Irrational numbers

### Numbers that can't be written as fractions— they're never-ending, non-repeating decimal. Square roots of +ve integers are either integers or irrational. Surds are numbers or expressions containing irrational roots

4

## What does BODMAS stand for and what is it used for

###
Brackets

Other

Division

Multiplication

Adding

Subtracting

Tells you the order in which these operations should be done

5

## What are multiples of a number

### A numbers times table

6

## What are factors of a number

### All the numbers that divide into the number

7

## What is a prime number

### A number which doesn't divide by anything, apart from itself and 1— i.e. It's only factors are itself and 1. ( the only exception is 1, which is NOT a prime number)

8

## How to find prime factors of a number

###
Use a factor tree:

1. Start with the number at the top, and split it into factors

2. Every time you get a prime, ring it

3. Keep going until you can't go further then write the primes out in order. If there's more than one of the same factor, write them as powers

9

## What is the LCM

### 'Least common multiple' is the smallest number bet that will divide by all the numbers in the question.

10

## What is the HCF

### 'Highest common factor' is the biggest number that will divide into all the numbers in the question

11

## How do you simplify a fraction

### Divide numerator and denominator by same number, till they won't go further

12

## How to multiply fractions

### Simplify then multiply too and bottom numbers separately

13

## How to divide fractions

### Flip the second and multiply

14

## How to add and subtract fractions

### Make sure denominators at the same then add/subtract numerators only

15

## How to find common denominator

### Find a number that all denominators divide into- this is common denominator

16

## How to fraction -> decimal

### Divide numerator by denominator

17

## How to decimal -> percentage

### x100

18

## How to percentage -> decimal

### Divide by 100

19

##
How to terminating decimal -> fraction

### The digits after the d.p go on top and a power of 10 on the bottom- with the same number of zeros as there were decimal places

20

## How to recurring decimal -> fraction

###
1. Name decimal x

2. Multiply x by a power of 10 to move it past the decimal point by one full repeated lump

3 subtract x by the power of 10 x to get rid of decimal part

4. Then divide to leave x and simplify if possible

21

## How to fractions into recurring decimals

### Find an equivalent fraction with all mined on denominator. The numerator will tell you the recurring part

22

## How to round to a given number of decimal places

###
- identify position of 'last digit' from the number of decimal places.

- then look at digit to the right (the decider)

-if decider 5 or above round up last digit, if decider 4 or less leave digit as is

23

## Rounding to significant figures

### The first s.f of any number is the first digit which isn't zero. The 2nd,3rd,4th,etc. s.f follow on immediately after the 1st, regardless of being zeros or not zeros

24

## How to estimate calculations

### Round all numbers to 1 sig fig

25

## How to estimate square roots

### Find 2 square numbers, one either side of the number you're given. Decide which number it's closest to, and mar a sensible estimate of the digit after the decimal point

26

## What are upper and lower bounds

### When a measurement is rounded to a given unit, the actual measurement can be anything up to half a unit bigger smaller

27

## What are the three rules of standard form

###
A x 10^n

1. Front number (A) must always be between 1 and 10

2. The power of 10 (n) is how far the decimal point moves

3. n is positive for big numbers and negative for small numbers

28

## Multiplying and dividing standard form

###
1. Rearrange to put front number and powers of 10 together

2. Multiply/divide front numbers, and use the power rules to multiply/divide the powers of 10

3. Make sure answer is in standard form

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