Expressions,+Formulae+and+Equations


 * 1. Expressions**
 * Expressions look like this: n + 8, n - 4, n/5, 3n
 * n is an unknown number
 * An expression doesn't have a solution
 * Expression can be 'evaluated' by substituting 'n' for a number
 * We can simplify expressions by //collecting like terms// e.g. a + a = 2a, 3b + 2b = 5b, 8y - 5y = 3y


 * 2. Equations**
 * Unlike expressions, equations can be solved
 * 'n' (or the unknown) has a particular value
 * n +7 = 12 is an equation, and so x + y = 15 (x + y can take many different values but they must always add to 15)
 * We can solve equations that have just one unknown using inverse operations e.g. y + 12 = 37 - the inverse of adding 12 is subtracting 12, so y = 37-12

//Mr Gardner works out his charges using this formula: Charge = call out fee + $5 x number of hours worked.// //If the call out fee is $35 and he works 8 hours then Charge = $35 + $5 x 8 (charge = $75)// //.//
 * 3. Formulae**
 * A formula is a rule for working something out
 * The letters in a formula always stand for something specific e.g. cost, speed or number of books
 * The formula is the rule which gives the relationship between these things
 * There is always more than one unknown in a formula
 * An example of a formula could be:
 * 4. Expression, equation or formula?**
 * [|Expression, equation or formula.pptx]


 * 5. Expressions quiz**
 * [|Expressions quiz.pptx]


 * 6. Exercises in your book**
 * Complete Exercise 3: Review 1 & 2
 * Complete Exercise 4: Review
 * Challenge: