Starter Using the numbers 12, 11 and 2, how can you make the numbers 46 and 34? Using the numbers 15, 7 and 2, how can you make the numbers 16 and 1? You may use the numbers more than once in each problem!

Use the Order of Operations We are Learning to…… Use the Order of Operations

Using the correct order of operations What is 7 – 3 – 2? When a calculation contains more than one operation it is important that we use the correct order of operations. The first rule is we work from left to right so, Stress that this rule is most important when repeatedly subtracting or dividing because when we subtract or divide numbers the order is important. When we repeatedly add or multiply the order is not important. 7 – 3 – 2 = 4 – 2 NOT 7 – 3 – 2 = 7 – 1 = 2 = 6

Using the correct order of operations What is 8 + 2 × 4? The second rule is that we multiply or divide before we add or subtract. 8 + 2 × 4 = 8 + 8 NOT 8 + 2 × 4 = 10 × 4 = 16 = 40

Brackets What is (15 – 9) ÷ 3? When a calculation contains brackets we always work out the contents of any brackets first. (15 – 9) ÷ 3 = 6 ÷ 3 = 2

Nested brackets Sometimes we have to use brackets within brackets. For example, 10 ÷ {5 – (6 – 3)} These are called nested brackets. We evaluate the innermost brackets first and then work outwards. Point out that it is common when using nested brackets to use a different style of bracket, such as the ‘curly’ brackets shown, to distinguish between the two pairs. Square brackets can also be used. 10 ÷ {5 – (6 – 3)} = 10 ÷ {5 – 3} = 10 ÷ 2 = 5

Using a division line 13 + 8 What is ? 7 When we use a horizontal line for division the dividing line acts as a bracket. 13 + 8 7 = (13 + 8) ÷ 7 = 21 ÷ 7 = 3

Using a division line 24 + 8 What is ? 24 – 8 Again, the dividing line acts as a bracket. = (24 + 8) ÷ (24 – 8) 24 + 8 24 – 8 = 32 ÷ 16 = 2

Multiplying by a bracket When we multiply by a bracket it is not always necessary to use the symbol for multiplication, ×. For example, 8 + 3(7 – 3) is equivalent to 8 + 3 × (7 – 3) = 8 + 3 × 4 = 8 + 12 = 20 Compare this to the use of brackets in algebraic expressions such as 3(a + 2).

Exponents What is 100 – 2(3 + 4)2 When exponents appear in a calculation, these are worked out after brackets, but before multiplication and division. 100 – 2(3 + 4)2 Brackets first, = 100 – 2 × 72 then Exponents, Introduce BIDMAS to remember the correct order of operations. = 100 – 2 × 49 then Division and Multiplication, = 100 – 98 and then Addition and Subtraction = 2

B E D M A S BEDMAS Remember BEDMAS: RACKETS XPONENTS IVISION ULTIPLICATION Remind pupils of the correct order of operations using the mnemonic: BIDMAS. A DDITION S UBTRACTION

Handout To succeed at this lesson today you need to… 1. Remember “BEDMAS” 2. This tells you the order to work out the question 3. Complete the assigned questions Handout

Solutions to BEDMAS questions 1) 2 + 12 = 14 2) 5 – 3 = 2 3) 20 – 12 = 8 4) 21 – 5 = 16 5) 1 + 6 – 5 = 2 6) 4 – 2 + 8 = 10 7) 6 + 28 = 34 8) 5 + 21 – 9 = 17 9) 56 – 19 = 37 10) 15 – 7 + 8 – 8 = 8 11) 45 – 30 – 8 = 7 12) 21 + 54 – 15 = 60 13) 12 + 21 = 33 14) 81 – 64 = 17 15) 14 – 3 + 2 – 9 = 4

Homework From the website watch the percentages videos nowyoudothemath.weebly.com MFM2P, Unit 1 Review