17-Aug-15Created by Mr.Lafferty Maths Dept Formulae Formulae expressed in words Working with Expressions Evaluating Formulae S4

17-Aug-15Created by Mr.Lafferty Maths Dept Starter Questions Starter Questions S4

17-Aug-15Created by Mr.Lafferty Maths Dept Learning Intention Success Criteria 2.Solving expressions showing working. 1.To explain the process of working out expressions by Formulae method. 1.Understand process of Formulae. S4 Formulae

17-Aug-15Created by Mr.Lafferty Maths Dept If a = 3 and b = 9 evaluate a + b 3+9= =12 Sub in a=3 Sub in b=9 S4 Formulae

17-Aug-15Created by Mr.Lafferty Maths Dept If a = 3 and b = 9 evaluate ab Sub in a=3 Sub in b=9 Remember ab means a x b a x b 3 x 9= =27 S4 Formulae

17-Aug-15Created by Mr.Lafferty Maths Dept If a = 3 and b = 9 evaluate 4b Sub in b=9 Remember 4b means 4 x b 4 x b 4 x 9= =36 S4 Formulae

17-Aug-15Created by Mr.Lafferty Maths Dept If a = 5 and b = 6 evaluate 1.a + b 2.ab 3.3a 4.b - a 5.4b 6.3ab =11 =30 =15 =1 =24 =90 S4 Formulae

17-Aug-15Created by Mr.Lafferty Maths Dept If a = 5 and b = 3 evaluate 2a + 4b Sub in a=5 Sub in b=3 Remember 2a means 2 x a 2 x a + 4 x b 2x2x 5+ 4x4x 3 = = = = 22 S4 Formulae

17-Aug-15Created by Mr.Lafferty Maths Dept If a = 5 and b = 3 evaluate a Sub in a=5 Remember a 2 means a x a a x a 5 x 5 = = = S4 Formulae

17-Aug-15Created by Mr.Lafferty Maths Dept b Remember a means a ÷ b If a = 15 and b = 3 evaluate a Sub in a = = =5 b Sub in b = 3 S4 Formulae

17-Aug-15Created by Mr.Lafferty Maths Dept If a = 2 and b = 6 evaluate 1)4a + 3b 2)a 2 3)b 2 5)4a 2 4)5b – 3a 6) b a =26 =4 =36 =24 =16 =3 S4 Formulae

Now try Ex 1 Ch14 (page 162) Formulae S4

Starter Questions 5 cm 2.5 cm 3 cm 4 cm 3 cm S4

Learning Intention Success Criteria 1.To explain how to work with formulae expressed in words. 1.Understand formulae expressed in words. Formulae 2.Solve problems given formulae in words. S4

Sometimes formulae are expressed in words. S4 Formulae A tile fitter charges £20 per hour. How much will he charge for 8 hours of work. C =20 x h For h = 8 C = 20 x 8 =£160

S4 Formulae The cost for hiring a carpet cleaner is £30 plus £3 a day How much will it cost to hire for a week. C =30+3d For d = 7 C = x 7 = £51

S4 Formulae Profit : Subtract how much you paid for goods in the first place from the amount you actually sold them for. How much profit did Daniel make if he bought a CD for £9.99 and sold it for £12 + Profit = 12 – 9.99 = £2.01

Now try Ex 2 Ch14 (page 164) Formulae S4

Starter Questions 1.Does x 4 = 11 or 20 S4

Learning Intention Success Criteria 1.To explain how to evaluate formulae 1.Understand the term formulae. Formulae 2.Be able to substitute values into formulae and evaluate properly using BODMAS. S4

Formulae A formula is the process calculating a quantity based on a known relationship e.g. Length, Area, Volume etc It is VERY important that we remember a keypoint when working with formulae. B O D M A S Brackets Other  squares and square root etc.... Divide Multiplication Addition Subtraction S4

Formula for Parallelogram Example 1 : Find the area of parallelogram. 9cm 3cm S4

Formulae for the Volume of a Sphere S4 r D D = diameter Q.If the above sphere has radius 10cm. Calculate it’s volume.

Q.If the above cone has radius 15cm and height of 10 cm.Calculate it’s volume. Formulae for Volume of a Cone r h S4

Now try Ex 3 Ch14 (page 166) Formulae S4