Algebraic Notation

Algebraic Notation

Algebraic notation

What is algebra?

• Algebra is a topic in mathematics that uses letters to represent general (or unknown) numbers

  • x  and y  are two unknown numbers
    

    • More information is needed to find their values

• Letters are also called variables

How do I write calculations in algebra?

• Writing mathematical ideas in letters is called using algebraic notation

• You can use + and – to mean add and subtract

  • a + b
    c + d – e

• However no symbol is used for multiplication

  • ab  (means a × b) 
    3ab  (means 3 × a × b)

• Fractions are used for division

  • $\frac{a}{b}$ (means a ÷ b)

• You can combine the ideas above

  • $ab+\frac{c}{3}$ (means a×b + c÷3)

  • The order of operations for numbers still works

    • work out a×b  and c÷3  before adding them together

• Powers (indices) and roots are the same as with numbers

  • a²  means a × a
    4a²  means 4 × a²

    • With the order of operations, a² happens before multiplying by 4

  • $\sqrt{a}$ means the square root of $a$

• Brackets work in the same way as they do with numbers

  • $3(a + b)$ means $3 \times (a + b)$

    • Add the a and b first, then multiply the result by 3