# L3 Numeracy Bridging Week 3 : Equations L3 Numeracy Week 4 : Equations and Algebra Expressions and (mainly linear) equations Task 1 In pairs report to your partner a) One word that describes how you feel about the last session. b) All the things you have done since last

weeks session to do with this course Line Up Take a card and arrange yourselves in numerical order to the value of your card. Outcomes Represent algebraic expressions in multiple ways (words, symbols, diagrams, tables)

Compare a range of methods of solving an algebraic problem and identify mistakes and misconceptions Form and solve simultaneous equations Relate the approaches to your own teaching and context Write down an algebraic expression that means. 1. Multiply n by 3, then add 4 2. Add 4 to n and then multiply the answer by 3

3. Add 2 to n and then divide the answer by 4 4. Subtract 4 from n 5. Square n and multiply the answer by 4 6. Add 4 to n and then square 7. Multiply n by 6 and then square 8. Add 2 to n; add three to n; and then multiply these expressions together. Words Symbols Card set A Algebraic expressions

Card set B Explanations in words In small groups Take turns in matching cards Always explain your thinking Challenge when you dont understand or need clarification Tables of Numbers Card set A Algebraic expressions Card set B Explanations in words

Card set C Tables of numbers Now match card set C to the others Areas Card set D Areas of shapes Card set A Algebraic expressions In your small group, Take turns in matching card set D to card set A Always explain your thinking

Challenge when you dont understand or need clarification Extension Can you draw a diagram to represent any of these expressions? 4x + 12 4(x + 3)

x2 - 5x 6 (x + 1)(x 6) 2x( x 1) 2x2 - x x2 x 6 (x 3)( x + 2) x2 + 5x + 6

x2 - 36 Plenary Malcolm Swan (2005) Improving Learning in Mathematics. Interpreting multiple representations Learners match cards showing different representations of the same mathematical idea. They draw links between different

representations and develop new mental images for concepts. Which maths topics could be taught using multiple representations? Solving linear Equations There are two common methods for solving linear equations. change the side, change the sign or

you always do the same to both sides. When used without understanding, such rules result in many errors. Common Errors For example: What is wrong with these examples Understanding the method

Doing the same to both sides is the more meaningful method, but there are two difficulties: Knowing how to change both sides of an equation so that equality is preserved Knowing which operations lead towards the desired goal. Solving Linear Equations Video explanations

Find the numbers. 1. Two numbers which when added give the value 5, and when subtracted give the value 1. 2. Two numbers multiply together to give 10 and add together to give -7 Can you write down the related equations? Application Can you think of some everyday examples where simultaneous equations may be

useful? Try these http://www.ehow.com/info_8710568_10-canused-everyday-life.html A problem A man buys 3 fish and 2 chips for 2.80 A woman buys 1 fish and 4 chips for 2.60 How much are the fish and how much are the chips? Can you form two equations to represent

this problem? Simultaneous Equations When you have two unknowns you need two equations 3f + 2c = 280 f + 4c = 260 (1) (2)

f = price of the fish in pence c = price of the chips in pence There are a few ways to solve these equations here is one Elimation: Step 1 Make one of the unknowns equal by multiplying. We know that: 3f + 2c = 280 (1)

f + 4c = 260 (2) Multiply (1) by 2 gives: 6f + 4c = 560 (3) Then (3)-(2) gives 5f = 300 Then solve this: f = 300/5 = 60 Therefore the price of fish is 60p Substitution: Step 2 Substitute this value into either (1) or (2):

3f + 2c = 280 (1) 3(60) + 2c = 280 180 + 2c = 280 2c = 280 180 = 100 c = 100/2 = 50 Therefore the price of chips is 50p Other Methods Graphical: Where two Straight lines cross http://www.bbc.co.uk/schools/gcsebitesize/maths/algebra/simultaneoushirev2.shtml

Substitution: Rearrange one of the original equations to isolate a variable, then substitute into other equation (useful for quadratics) http://www.bbc.co.uk/schools/gcsebitesize/maths/algebra/simultaneoushirev1.shtml Exam Papers It is sometimes useful to work with past papers to explore a topic. If there are different possible methods, one

approach is to compare them.. Consider 5x + 2y = 11 4x 3y = 18 Ali, Xo, Edward and Kristina all attempted to solve the equations in different ways Marking Students Work In your small group, discuss their answers: What did you like about the answer?

What method was used? Was the method clear, accurate, efficient? What errors were made? How might the work be improved? Are there any specific teaching strategies that might be useful in addressing any problems highlighted by the answer? Plenary Swan Again Analysing reasoning and solutions

Learners compare different methods for doing a problem, organise solutions and/or diagnose the causes of errors in solutions. They begin to recognise that there are alternative pathways through a problem, and develop their own chains of reasoning. When do you show and compare different methods for a problem? Examples

L3 A0N (past paper) A charity collection bottle contained 1 494 two-pence and five-pence coins with a total value of 47.46 a) Use this information to form two equations about the number of two pence coins and the number of fivepence coins in the bottle. 1 mark b) Calculate the number of two-pence coins and the number of five-pence coins in the bottle. 2 marks c) Show how you can check your answers to part b 1 mark

Practise Simultaneous Equations: for each question A) Use the information to form two equations B) Solve the equations to find two unknowns C) Show how you can check your answers For help and examples see: http://www.bbc.co.uk/schools/gcsebitesize/maths/algebra/simultaneoushirev1.shtml More Practice: CIMT online exercises

More online help Video with elimination method https://corbettmaths.com/2013/03/05/simulta neous-equations-elimination-method / Practise questions with answers http:// www.mathsgenie.co.uk/resources/87_simult aneous-equationsans.pdf

Check Outcomes How well can you. Represent algebraic expressions in multiple ways (words, symbols, diagrams, tables) Compare a range of methods of solving an algebraic problem and identify mistakes and misconceptions Form and solve simultaneous equations Relate the approaches to your own teaching and context