Algebra Vocabulary & Literacy Variable Formula Coefficient Substitution Expression Terms Powers Brackets

n + 3 n - 8 n + n + 3 + n – 8 = 3n - 5 Using variables Make up some more problems like this. Mr Ewins is n years old. His sister is 3 years older than him. Write an expression for his sister’s age. n + 3 His brother is 8 years younger than him. Write an expression for his brother’s age. n - 8 Write an expression for their TOTAL age n + n + 3 + n – 8 = 3n - 5

n + 3 2 - n n + n n ÷ 2 2n ½ n 3 + n n x n n - 2 Same or different? Write all these expressions down. n + 3 2 - n n + n n ÷ 2 2n ½ n 3 + n n x n n - 2 Connect expressions that are the same.

n 2n 10n Letters and numbers This packet contains n sweets. How many sweets will there be in …. (a) 2 packets? 2n 10n (b) 10 packets?

Letters and numbers How many sweets will there be here? n = n + 3

Letters and numbers How many sweets will there be here? = 2n + 6

Letters and numbers How many sweets will there be here? = 3n + 13

2n n + 5 15 3n + 1 20 - n Letters and numbers n = 5 n = 8 Copy and complete this table Expression n = 5 n = 8 n = 10 n = 20 2n n + 5 15 3n + 1 20 - n

Letters and numbers Copy and complete this table Expression n = 5 n = 8 n = 10 n = 20 2n 16 n + 5 15 3n + 1 20 - n 10 20 40 10 13 25 16 25 31 61 15 12 10

Using variables In a cinema, each row has 28 seats. Show clear working to find the number of seats in….. (a) 5 rows (b) 12 rows (c) n rows

Using variables A window cleaner charges £5 for every window he cleans. Show clear working to find the amount of money he earns by cleaning….….. (a) 8 windows (b) 15 windows (c) n windows Make up two more problems like this.

Using variables – extension question Mr Ewins needs to order some maths stock. He needs compasses, rulers and protractors. Compasses are 20p each, rulers are 30p each and protractors are 15p each. Write an expression for the total cost of his order using variables (letters).

Using variables Compasses are 20p each, rulers are 30p each and protractors are 15p each. Let.. c be the number of compasses needed at 20p each r be the number of rulers needed at 30p each P be the number of protractors needed at 15p each. 20 x c + 30 x r + 15 x p = total cost

T = 20 w + 15 Using formulae This is how to cook a chicken Time = 20mins × w + 15 mins T = 20 w + 15 How long does a 4kg chicken take to cook? T = 20 x 4 + 15 T = 95mins

C = 6 h + 10 Using formulae Cost = £6 × h + £10 The cost of hiring a sander for h hours Cost = £6 × h + £10 C = 6 h + 10 How much will it cost to hire a sander for 6 hours? C = 6 x 8 + 10 C = £58

V = ab − c Using formulae Work out the value of V when : i) a = 5, b = 3 and c = 8 ii) a = 12, b = 4 and c = – 5

T = 3m2 + 4n Using a formula Work out the value of T when : (i) m = 6 and n = 9 (ii) m = – 6 and n = – 9

P = 0.9E The exchange formula for pounds and euros Using a formula The exchange formula for pounds and euros P = 0.9E Work out the value of €300 in pounds Work out the value of £300 in euros

Using a formula Work out the value of P when k = 30. Give your answer to 1 d. p.