YEAR 9: SPRING TERM Number 2 (8-10 hours) Place value (36–47) Fractions, decimals, percentages, ratio and proportion (60–81) Calculations (82–107, 110–111) Calculator methods (108–109) Solving problems (28–29) Teaching objectives for the main activities CORE From the Y9 teaching programme A. Understand the order of precedence and effect of powers. B. Use known facts to derive unknown facts; extend mental methods of calculation, working with decimals, fractions, percentages, factors, powers and roots; solve word problems mentally. C. Make and justify estimates and approximations of calculations. D. Use efficient methods to add, subtract, multiply and divide fractions, interpreting division as a multiplicative inverse; cancel common factors before multiplying or dividing. E. Check results using appropriate methods F. Extend knowledge of integer powers of 10; multiply and divide by any integer power of 10. G. Use rounding to make estimates; round numbers to the nearest whole number or to one or two decimal places. H. Know that a recurring decimal is an exact fraction. I. Use standard column procedures to add and subtract integers and decimals of any size, including a mixture of large and small numbers with differing numbers of decimal places; multiply and divide by decimals, dividing by transforming to division by an integer. J. Check results using appropriate methods. K. Use a calculator efficiently and appropriately to perform complex calculations with numbers of any size, knowing not to round during intermediate steps of a calculation; use the constant, and sign change keys, function keys for powers, roots and fractions, brackets and the memory. L. Enter numbers into a calculator and interpret the display in context (negative numbers, fractions, decimals, percentages, money, metric measures, time). (reduce since added into Number 1) M. Solve substantial problems by breaking them into simpler tasks, using a range of efficient techniques, methods and resources, including ICT; use trial and improvement where a more efficient method is not obvious. Unit: Number 2 Year Group: Y9 Number of 1 Hour Lessons: 8 to 10 Class/Set: Core Oral and mental Objectives j, h, k, i. Complements of decimals to 1, 10, 20 etc. Explore methods extend as appropriate. How would you calculate 36 x 25? So what is 36 x 26? So what is 36 x 24? Main Teaching (2 to 3 ) lessons Objective I (+ and -) Consolidate column addition and subtraction of decimals as needed. (Discuss jottings and number lines - objective i) Use in context of money and measurement of length etc. Objective F, I ( x) Consolidate understanding of decimals and their multiplication by 10, 100, 1000 etc. Extend to multiplication by 101, 102, 103 etc. making explicit the clues given by the powers. Move to division and set scenarios as below. Notes Key Vocab. Product. Powers Plenary What are the main mistakes people make when adding and subtracting decimals? Why is 0.3 x 0.2 = 0.06? How many ways can you express nine hundredths? Give me an informal jotting method of using 16 x 25 to get 1.6 x 24. Focus on solutions to some of the solutions to key problems set in the lesson. Note and reinforce techniques developed. 0.4 = 4 ÷ 10 = 4/10 0.07 = Model practical application from the lesson. 0.005 = Extend to 3.6 x 25 then 3.6 x 2.5 to assess knowledge and understanding. Try estimates to check answers and or calculators. If possible model 3.6 x 2.5 = 36 25 900 x 9 10 10 100 Linking the two skills. Use these techniques to solve problems including written questions on area and percentages which lead to the product of decimals. (Integrate or teach specifically, rounding answers objective G). Oral and mental Objectives g and f. Simplifying fractions by cancelling. Find equivalent fractions with larger numerators and denominators. How does this relate to 36 36 10 3.6 ? 10 10 10 What happens to a fraction if we increase the denominator? What happens to a fraction if we increase the numerator? Main Teaching (1 – 2 lessons) Revisit skills from previous lessons. Objective I (division) Explore the meaning of division. Model and develop understanding that 1 3 10 30 (obj. D interpret 10 division is a multiplicative inverse). Develop into practical situation. E.g. how many 10cm strips could I cut from a 3metre wooden board? If possible extend to negative index notation for powers of 10. 3 3 10 30 30 Model 3 0.1 0.1 0.1 10 1 Develop this technique to support division by decimals e.g. making the denominator or divisor a whole number whilst keeping the same ratio. 3 ÷ 0.1 = 3 Notes Key Vocab. Multiplicative inverse Generalise Divisor Plenary If I say 23 ÷ 0.1 = 2.3 how do you know this is wrong? If I say 23 ÷ 0.1 = 230 how does 1 this help me tackle 23 ? 10 How can I extend this to help me with other questions? What generalisations can we make? How do powers of 10 help us with multiplication and division? Highlight what has to be remembered. Oral and mental Obj l, m, n, Revisit mult. and division by powers of 10 Match answers to questions and solutions. Use a target board Use a mixture of numbers and signs on the board pointing to two numbers and a sign and asking for a solution. Matching equivalent fractions Converting mixed numbers to improper fractions etc. Mental addition of fractions. Counting up in eighths on a number line with cancelling etc Main Teaching Objectives D, B, C and E (2 - 3 lesson). Revisit understanding of fractions cancelling and equivalent fractions – make links to percentages and decimals. Revisit or teach addition and subtraction of fractions – extend to mixed number techniques. (Objective L Model with calculator). Notes Key Vocab. Cancel Simplest Lowest terms Mixed number Improper fraction. Proportional Common factor Plenary Generalise on findings. Model cancelling with pictures or ask students to give a pictorial explanation of cancelling. Ask students to invent some common mistakes in adding or subtracting fractions. Share the inventions and ask other students to say what is wrong. Model some addition of fractions and equivalent additions using decimals. Model multiplication of fractions e.g. 3 2 3 2 of 4 3 4 3 2 Draw a 4 by 3 table and shade in .Then shade in 3 2 6 3 of the . Show the result is of the original 3 12 4 table and develop a system for efficiently multiplying fractions. Look at short cuts in cancelling. Extend to mixed numbers. (Partitioning perhaps and using the grid multiplication method). Model division with concrete examples with 3 3 diagrams e.g how many in ? Develop a system 8 4 using multiplicative inverse idea. (Objective L Model with calculator) Revisit generalisation Ask students to model a solution pictorially. Relate to percentages. Model common mistakes. Model some questions that can be 1 2 1 1 done mentally. E.g , 1 2 3 2 2 Why is multiplying by one tenth the same as dividing by 10 etc.? Relate to percentages. Oral and mental Objective g Increase $1.20 by 25%. Ask groups of students or all the students to do it. Mentally Using multiplication of decimals. Using multiplication by a¼ Using multiplication by a mixed number (1 ¼). By ratio Main Teaching Objectives K, L, M and E. (2 lessons) Begin by looking at an OHP of a calculator and in groups identifying what keys do. After feedback this may be useful in assessment for learning (which areas to address). Use the power keys efficiently and model their use. Use this to establish the order of priorities with a4 2 powers. E.g. (a2 - 2a3 + ) might be worth 2 discussing or evaluating each term in the expression for various values of a. Notes Key Vocab. Index Power Reciprocal Trial and improvement Term Exponent Discuss outcomes. Discuss use of a calculator. Objective H How can I get 0.3333 going on forever from a calculation? Develop to other recurring decimals. What do they have in common? Stress that as vulgar fractions they are exact values. A collection of questions to be done in groups or pairs followed by feedback on methods used is a useful strategy. Some groups can be restricted e.g. no memory used, no power key, no brackets. These could be in a pack of cards drawn at random for each question. Discussion should centre on efficiency estimation and communicating the methods used. Extend to worded questions perhaps drawn from SAT data base or framework. Challenge students to solve questions with the smallest number of key presses. Establish understanding of priorities of powers. Assess knowledge of key use on calculator. Challenge students to estimate answers to questions – invite students to model solutions. You may want to use trial and improvement to calculate roots before using the root function keys. Reinforce the use of brackets, the order of priorities of a calculator, the change of sign key and insist on estimates as ways of checking answers. Much of this will be revision from Y8 work. Plenary Model some SAT questions. Model questions from real life. Check key language. SHEETNUMB2-1 For examples