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Basic Skills

**Negative**Numbers- same signs = +ve
- different signs = -ve

- Add and Subtract Fractions
- Common
**denomenator**

- Common
- Multiply and Divide Fractions in IGCSE Maths
- Multiplying: x tops, x bottoms
- Dividing: flip 2nd fraction then x

- Basic %
- Fraction x100

- Fraction/ Decimal/ %
- x or / by 100

Number

- Prime
**Factorisation**- factor tree

- In IGCSE Maths, you can find HCF and LCM by
- factor tree, venn diagram
- Venn diagram:
- put no.s there are in common in centre
- fill in rest of circles with other no.s
**HCF**: intersection no.s x together**LCM**: all no.s in diagram x together

**Recurring Decimals**- answers is always '/9' or '/99' or '999' etc

- Rounding
**more than**5- round up- l
**ess than**5- round down

- Reverse %
- divide amount given by
**100-**given % - TV reduced by 15% in sale now £100- original amount: 100/(100- 15)

- divide amount given by

End of this topic!

Drafted by Gina (Mathematics)