Unformatted text preview: Decimals
Revision Level E Add & Subtract Decimals Multiplying by 2 Simple Decimals Dividing 2 Simple Decimals Rounding to Any Number of Decimal Places Rounding to Significant Figures Profit and Loss Hire Purchase Salaries & Overtime Foreign Exchange
13 Feb 2012 Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Starter Questions
If a = 7 b = 4 and c = 10
www.mathsrevision.com Write down as many equations as you can e.g. a + b = 11 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Decimals
Revision of Level E
Learning Intention Success Criteria 1. To round to 1 decimal place. 2. To multiply and divide by 10, 100 and 1000. www.mathsrevision.com 1. To revise Level E work. 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Decimals
Revision Level E 1. What does 6 stand for in 0.26 ? 6 hundredths 0.06
Shop A 80p Shop B 79p B is cheaper! www.mathsrevision.com 2. What number lies between 0.1 and 0.0.2 ? 3. Round to 1 decimal place 34.055 4. Calculate 4.76 x 100 5. Calculate 567.89 1000 476 0.56789 34.05 6. Shop A sell 25 CD's for 20 and Shop B sells 40 CD's for 31.40. Which shop is the cheapest.
13 Feb 2012 Created by Mr. Lafferty Maths Dept. Decimals
Revision Level E www.mathsrevision.com Now try Exercise 1 Ch13 (page 56) 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Starter Questions
1. Two numbers add to give 12 and divide to give 3. Find the two numbers. 2. Two numbers subtract to give 5 and multiply to 24. Find the two numbers. 3. Make your own question up.
13 Feb 2012 Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Addition & Subtraction
Learning Intention Success Criteria 1. Remember to keep decimal point in line. 2. Make use of trailing 0's when needed. Decimals www.mathsrevision.com 1. To explain how to add and subtract decimal numbers. 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Addition & Subtraction Example : 3.2 + 0.487 + 5.73 Decimals www.mathsrevision.com 3.200 0.487 +5.730 9.417 1 11
13 Feb 2012 Created by Mr. Lafferty Maths Dept. Keep point in line Addition & Subtraction Example : 6.2 3.19 + 1.783 Decimals 6.200 +1.783 7.983 3.190 4. 793
13 Feb 2012 Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Add first Then subtract Addition & Subtraction Decimals www.mathsrevision.com Now try Exercise 2 Ch13 (page 58) 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Starter Questions
1. ( 5 ) ( 6 ) + 11 www.mathsrevision.com 2 . C a lc ula t e 15 % o f 6 0 3 . W h a t is t h e p e r im e t e r a nd a r e a o f a s q ua r e wit h le ng t h 4 c m . 4 . Find t h e va lue o f x 3 x 9 = 2 7
13 Feb 2012 Created by Mr. Lafferty Maths Dept. Decimals
Simple Multiplication
Learning Intention Success Criteria 1. Use rules to do simple multiplicaton. www.mathsrevision.com 1. Explain how to do simple multiplcation. 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Decimals
Simple Multiplication Example 1 : 0.6 x 0.4 6 x 4 = 24 0. 24 www.mathsrevision.com 2 digits after decimal place Example 2 : 0.09 x 0.3 9 x 3 = 27 0. 027 13 Feb 2012 3 digits after Created by Mr. Lafferty Maths Dept. decimal place Decimals
Simple Multiplication Example 3 : 0.071 x 0.5 71 x 5 = 355 4 digits after decimal place 0. 0355 www.mathsrevision.com
13 Feb 2012 Created by Mr. Lafferty Maths Dept. Decimals
Simple Multiplication www.mathsrevision.com Now try Exercise 5 Ch13 (page 62) 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Starter Questions
1. Simplf y t he r at io 57 : 19 www.mathsrevision.com 1 2 . Ho w m a ny d e g r e e s in a n of a cir cle 8 3. I got $ 250 f or 100. How much would I get f or 1. 4. Put in or der , smallest f ir st . 0. 05, 0. 21, 0. 01, 0. 026
13 Feb 2012 Created by Mr. Lafferty Maths Dept. Division of a Decimal
Learning Intention Decimals
Success Criteria 1. Understand simple rule for dividing decimals. www.mathsrevision.com 1. To explain how to division simple decimal numbers. 2. Use rule to do calculations. 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Division of a Decimal Decimals Do not attempt to divide by a decimal, multiply the divisor so it is a whole number first. www.mathsrevision.com Example 1 : 3.5 0.7 35 7 = 5 x 10 x 10 Example 2 : 0.8 0.2
13 Feb 2012 8 2 = 4 Created by Mr. Lafferty Maths Dept. Division of a Decimal Decimals Do not attempt to divide by a decimal, multiply the divisor so it is a whole number first. www.mathsrevision.com Example 3 : 0.036 0.04 3.6 4 = 0.9 x 100 Example 4 : 24 3000
13 Feb 2012 24 31000 = 0.008 Created by Mr. Lafferty Maths Dept. Division of a Decimal Decimals www.mathsrevision.com Now try Exercise 6 Ch13 (page 63) 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Starter Questions
The answer to the question is
www.mathsrevision.com 60
Write down as many questions as you can 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Rounding to Any Number of Decimal Places
Learning Intention Success Criteria 1. Understand rule for rounding to any number of decimal places. Decimals www.mathsrevision.com 1. To explain how to round to any number of decimal places. 2. Use rule to round numbers. 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Rounding to Any Number of Decimal Places When rounding to : 1 decimal place look at 2nd decimal figure 2 decimal place look at 3rd decimal figure 3 decimal place look at 4th decimal figure 4 decimal place look at 5th decimal figure e.g. 2.46 e.g. 6.456 e.g. 3.7846 e.g. 13.1146 Decimals www.mathsrevision.com 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Rounding to Any Number of Decimal Places Example : The number 4.2615937 Rounded to 1 decimal place, the number is Rounded to 2 decimal place, the number is Rounded to 3 decimal place, the number is Rounded to 4 decimal place, the number is 4.3 4.26 4.262 4.2616 Decimals www.mathsrevision.com 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Rounding to Any Number of Decimal Places Decimals www.mathsrevision.com Now try Exercise 7 Ch13 (page 64) 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Starter Questions
Level F Q1. Round t he f ollowing t o 2 decimals places. (b) 4. 55732 (c) 3. 98111 www.mathsrevision.com (a) 3. 5647 Q2. Writ e in st andard f orm. (a) 12300 (b) 0. 0034 (c) 0. 0005 Q3.
13 Feb 2012 Expand out 4h(h 2  2h  3)
Created by Mr. Lafferty Maths Dept. Significant Numbers
Level F Learning Intention Success Criteria 1. To know the meaning of significant number. 2. Apply knowledge to problems. www.mathsrevision.com 1. To understand the term significant number for decimals and whole numbers. 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Significant Numbers
Level F In mathematics a figure or digit is significant if it gives an idea of both: www.mathsrevision.com (i) Quantity (ii) Accuracy
IMPORTANT : If zero's are employed just to position the decimal point then they are considered NOT significant. e.g. 506 cm 50.6 cm 0.506 cm 0.00506 cm Has 3 significant figures. Has 3 significant figures. Has 3 significant figures. Has 3 significant figures.
Created by Mr. Lafferty Maths Dept. 13 Feb 2012 Significant Numbers
Level F IMPORTANT : When dealing with WHOLE NUMBERS you need More information before you can tell if trailing zero's are significant. www.mathsrevision.com Question ? How many significant figures is this number to. 360 Is it 2 or 3 !!! If I said there are 360 deg. in a circle. How many significant figures. If I said 359 to the nearest ten is 360. How many significant figures. YOU NEED TO KNOW THE CONTEXT OF THE QUESTION WHEN DEALING WITH WHOLE NUMBERS WITH TRAILING ZEROS.
13 Feb 2012 Created by Mr. Lafferty Maths Dept. 3 2 WORK OUT WHAT THE ZERO MEANS Significant Figures
Decimals 0.001090 Level F www.mathsrevision.com To the left of The number Middle of the number To the right of the number Not Significant Always Significant Always Significant Whole Numbers 03060
To the left of The number Middle of the number ? Depends More Info. Not Significant
13 Feb 2012 Always Significant
Created by Mr. Lafferty Maths Dept. Read Question Significant Numbers
Level F www.mathsrevision.com Now try Ex 8 Ch13 (page 65) 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Starter Questions
S3 Credit Q1. 0.5 + 5 x 8 www.mathsrevision.com Q2. Multiply out the brackets (a) 2 6 (x 3 ) (b ) (x 4 ) ( 3 x + 5 )
Q3. Find g wh e n 7 g = 3 2 Q4. I f a = 7 , b = 6, c = 3 Find
ac 2  b 2
13 Feb 2012 Created by Mr. Lafferty Maths Dept. Profit and Loss
Level F Learning Intention Success Criteria 1. To know the meaning of the terms PROFIT and LOSS. 2. Apply knowledge to calculations. www.mathsrevision.com 1. To understand the terms profit and loss. 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Level F Profit and Loss
Profit : When you sell something for MORE than you bought it. PROFIT = Selling Price Buying Price Loss : When you sell something for LESS than you bought it. www.mathsrevision.com LOSS = Buying Price Selling Price
13 Feb 2012 Created by Mr. Lafferty Maths Dept. Level F Profit and Loss
Example 1 If I buy a Playstation for 100 and sell it for 120. www.mathsrevision.com I have made a PROFIT of 120100 = 20 Example 2 I bought a bunch of flowers for 5.50 and tried to sell them for a profit. But I found it difficult to sell them. I sold them for 4.00 before they went off. I made a LOSS of
13 Feb 2012 5.50 4.00 = 1.50
Created by Mr. Lafferty Maths Dept. Profit and Loss
Level F www.mathsrevision.com Now try Ex 9 Ch13 (page 67) Q1 Q3 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Hire Purchase
Level F Learning Intention Success Criteria 1. To know the meaning of the terms HIRE PURCHASE. 2. Apply knowledge to calculations. www.mathsrevision.com 1. To understand the terms Hire Purchase. 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Level F Starter Questions
Q1. Expand out 2j (k 5g + 4jk) www.mathsrevision.com Q2. Find all the missing angles 25o Q3. Find m wh e n 5 5 = 13 14 m Q4. I f a = 9 , b = 7 , c = 4 Find
ab  c 2
13 Feb 2012 Created by Mr. Lafferty Maths Dept. Level F Hire Purchase
Hire Purchase : When you pay for goods by putting down a deposit and then paying the rest up in small fixed payments over a period of time. Normally you pay more for the goods using this method. www.mathsrevision.com
13 Feb 2012 Created by Mr. Lafferty Maths Dept. Level F Hire Purchase
Buying Products www.mathsrevision.com Hoover Cash Price 365.50 or by H.P. 75 deposit + 12 Payment 28.80 How much more do you pay by using Hire Purchase Total H.P. price = 75 + 12 x 28.80 = 420.60 Difference in price = 13 Feb 2012 420.60 365.50 = 55.10 Created by Mr. Lafferty Maths Dept. Hire Purchase
Level F www.mathsrevision.com Now try Ex 9 Ch13 (page 68) Q4 Q7 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Level F Starter Questions
Q1. Expand out 2a (a c + 4ab) www.mathsrevision.com Q2. Find the missing angle 22o Q3. Find g wh e n 7 8 g = 9 5 Q4. I f a = 9 , b = 7 , c = 4 Find
ab  c 2
13 Feb 2012 Created by Mr. Lafferty Maths Dept. Salaries & Overtime
Level F Learning Intention Success Criteria 1. To know the meaning of the terms Salary and Overtime. 2. Apply knowledge to calculations. www.mathsrevision.com 1. To understand the Salary and Overtime. 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Level F Salaries & Overtime
Salary : How much a person is paid to do a job. Can be measured weekly, monthly or annually. www.mathsrevision.com Overtime : Extra work outside normal work time. Usually at night or weekends. 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Level F Salaries & Overtime
Example 1 : www.mathsrevision.com Mick the mechanic gets paid 1725.20 a month. How much is his annual salary. Annual Salary is = 1725.20 x 12 = 20 702.40 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Level F Salaries & Overtime
Example 2 : Claire the clerkess gets an annual salary of 19 003.40. How much is her weekly wage. Weekly Salary is = 19 003.40 52 = 365.45 www.mathsrevision.com
13 Feb 2012 Created by Mr. Lafferty Maths Dept. Level F Salaries & Overtime
Example 3 : Percy works for 12.90 per hour. His overtime rate is "time & a half". What does he get paid for 4 hours overtime. 4 hours Overtime is = 4 x 12.90 x 1.5 = 77.40 www.mathsrevision.com 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Salaries & Overtime
Level F www.mathsrevision.com Now try Ex 9 Ch13 (page 68) Q8 Q14 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Level F Starter Questions
Q1. Expand out 2a (a c + 4ab) www.mathsrevision.com Q2. Find two missing angles 32o Q3. Find y 1 y =10 0 5 Q4. The answer is 45. What is the queston. 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Foreign Exchange
Level F Learning Intention Success Criteria 1. Be able to convert 's to another currency. 2. Be able to convert back to 's. www.mathsrevision.com 1. To explain how to convert 's to another currency and vice versa. 13 Feb 2012 Created by Mr. Lafferty Maths Dept. Level F Foreign Exchange
The currency in most of Europe is the euro The exchange rate is approximately 1 1.54 www.mathsrevision.com Think going on holiday ! Converting 's to Euros simply multiply (a)
13 Feb 2012 To change 80 to euros
Created by Mr. Lafferty Maths Dept. 80 x 1.54 = 123.20 Level F Foreign Exchange
Coming back from holiday we want to do the opposite i.e. euros to 's The exchange rate is approximately 1 1.54 www.mathsrevision.com Think back from holiday ! Converting Euros 's to 's simply divide To change 616 to 's
13 Feb 2012 Created by Mr. Lafferty Maths Dept. 616 1.54 = 400 Foreign Exchange
Level F www.mathsrevision.com Now try Ex 9 Ch13 (page 70) Q15 Q20 13 Feb 2012 Created by Mr. Lafferty Maths Dept. ...
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