S2 (2.2) Percentages.notebook September 24, 2015

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1 Daily Practice Q1. Round to the nearest unit Q2. Find 25% of 240 L.I: Today we will be revising how to find a fraction of an amount and use this information to help us find percentages of amounts. Q x 5 Q4. Factorise 16ax + 20x S.C: We will be successful if we can find a fraction of an amount. We will also be able to find common percentages of amounts. Q5. Mutliply out and simplify 6(2x + 1) - 5x Percentages A percentage is a fraction whose denominator is 100. Need to be able to: - Simplify a fraction - Find equivalent fractions - Find fractions of amounts Recap: Finding fractions of amounts The top of a fraction is called the numerator. The bottom of a fraction is called the denominator. *Divide by the denominator multiply your answer by the numerator* Examples: (i) Find 2 / 3 of 33 (ii) Find 4 / 7 of 2849 (iii) Find 3 / 8 of 1604 Recap: Finding fractions of amounts Daily Practice Q1. Multiply out and simplify 7x - 2(3x + 4) Q2. Factorise x 2-4x Q x 5 Q4. Find 75% of 360 Q5. Find the median and range of -2, 1, 3, 4, 7, 6, 8

2 L.I: Today we will be learning how to find a percentage of an amount. Familiar Percentages 10% 25% 50% 75% S.C: We will be able to find a percentage of an amount. Percentages 1% 800 5% 50% 1% = 8% = 20% = 10% 75% 25% 13% = 50% = 98% = Percentages To find a percentage of an amount - Think about the percentage as a fraction over 100, then it is the same as finding a fraction of an amount (You may be able to simplify the fraction first). I can find a percentage of an amount Success? Examples: Work out the following a) 8% of 700 b) 90% of 800 c) 28% of 2000

3 Daily Practice Q1. Find 5% of 800 Examples: Q2. Round to 1 decimal place 35% of % of 720 Q3. Given a = 2.5 and b = 3, find the value of 3a +2b Q (-7) Q5. Multiply out 7-3(2x + 2) Percentages of amounts Questions: a) 1% of 1000 b) 4% of 300 c) 2% of 800 d) 9% of 100 e) 35% of 800 f) 19% of 500 g) 28% of 700 h) 34% of 300 Daily Practice Q1. Find 30% of 720 Q5. Find the mean of 5, 6, 7, 8, 1 Q2. 5 x 6-2 x 3 i)20% of 3000 j) 43% of 900 k) 45% of 7000 l) 38% of 1000 m) 14% of 420 n) 30% of o) 8% of 120 p) 65% of 160 q) 2% of 34 r) 45% of 2.5 s) 5% of 78 t) 16% of Q x 0.08 Q4. Find 3 / 7 of 427 Percentage Increase/decrease *Appreciation means an increase in value and depreciation means a decrease in value. Examples: L.I: Today we will be learning how to find a percentage increase/decrease of an amount. 1. A house was worth and it appreciated by 4%. What is the new value of the house? S.C: I will be successful if I can find a percentage increase/ decrease of an amount both by using a calculator and noncalculator. 2. A dress costs 52 and is in the sale with 15% marked off. How much is the dress now?

4 62 48 decrease by 15% Swimsuit 26 decrease by 13% CD player 89 decrease by 36% Speakers decrease by 25% Shorts 42 decrease by 5% decrease by 16% Track suit 66 decrease by 23% 9.50 (b) 348 (c) Find these employees new annual pay Assistant weekly wage % increase Supervisor weekly wage % increase weekly wage % increase Success? I can find a percentage increase and decrease. Daily Practice Q1. Round to 2 decimal places Q2. Find 34% of 800 Q3. Multiply out and simplify -2(2x + 1) + 5x - 2 Q4. If h = 2 and g = 4, what is the value of 2h + 3g? Q x 4 Writing a fraction as a percentage To write a fraction as an equivalent fraction over 100. Think about how you can get an equivalent fraction. L.I: Today we will be learning how to write a fraction as a percentage. For example: S.C: I will be successful if I can convert a fraction that has a denominator which is a factor of 100 to a percentage.

5 Writing a fraction as a percentage Write the following fractions as percentages: Q1. (i) (ii) (iii) (iv) (v) (vi) *(vii) *(viii) Q2. (a) Jenny got a result of 14 out of 25 in her homework. Write this as a percentage (b) Bill ate 7 of the 10 slices of the pizza, what percentage is this? (c) Darragh says the probability of rolling a dice and getting an even number is 3 out of 6. Write this as a percentage Writing a fraction as a percentage Match the following fractions with their equivalent percentages Success? I can write a fraction as an equivalent fraction over 100 (a percentage) if it has a denominator that is a factor of % 40% 85% 74% 92% 50% 75% 90% 60% 25% Daily Practice Q1. Round to 1 decimal place Q2. Find 17.5% of 800 Q L.I: Today we will be learning how to write all fractions as decimals and then as percentages. S.C: I will be able to write a fraction as a decimal and as a percentage. Q4. Find 3 / 7 of 287 Q5. 10% of Homework Online due

6 Fractions as decimals How do you convert a fraction into a decimal? Think about fractions like Examples: Convert the following fractions into decimals (a) (b) (c) (d) Fractions as decimals Convert the following into decimals Decimals as percentages (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) (l) (m) (n) (o) (p) Calculator: Round to 2 d.p. when needed (q) (r) (s) (t) (u) Decimals as percentages Decimals as percentages Examples: Write the following as percentages Convert the following into percentages: 1) ) ) 0.6 4) ) 0.81 (a) 0.35 (b) 0.05 (c) (d) 6) ) 0.2 8) 9) 10) 11) 12) 13) 14) 15) 16) Write 16 out of 27 as a percentage 17) Jo got 14 out of 17 in her test, express this as a percentage. 18) Kirsty ate 12 out of 20 cupcakes, write this as a percentage 19) Ciaran bought a car for 3000 and sold it for 1750, write the loss he made as a percentage 20) Abby got a result of 28 out of 40, write as a percentae

7 Success? Daily Practice I can convert any fraction into a decimal and then into a percentage. 20 Questions Mental Maths L.I: Today we will be completing a check-up on percentages. S.C: I will be able to answer various questions on percentages. Homework Online due