Transcript Slide 1

Decimals
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MNU 3-03a
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
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Starter Questions
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MNU 3-03a
If a = 7 b = 4 and c = 10
Write down as many equations as you can
e.g. a + b = 11
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Decimals
Revision of Level E
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MNU 3-03a
Learning Intention
1.
To revise Level E work.
Success Criteria
1. Understand how to round
to 1 decimal place.
2. Apply rules for multiplying
and dividing by 10, 100 and
1000.
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Decimals
Revision Level E
MNU 3-03a
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1. What does 6 stand for in 0.26 ?
6 hundredths
2. What number lies halfway between 0.1 and 0.02 ?
0.06
3. Round to 1 decimal place 34.75
34.8
4. Calculate 4.76 x 100
Shop A 80p
Shop B 79p
476
5. Calculate 567.89 ÷ 1000
0.56789
B is
cheaper!
6. Shop A sell 20 CD’s for £16 and Shop B sells
40 CD’s for £31.60. Which shop is the cheapest.
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Decimals
Revision Level E
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MNU 3-03a
Now try Exercise 1
Ch13 (page 56)
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Starter Questions
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MNU 3-03a
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.
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Decimals
Addition & Subtraction
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MNU 3-03a
Learning Intention
1.
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We are learning to add
and subtract decimal
numbers.
Success Criteria
1. Remember to keep decimal
point in line.
2. Make use of trailing 0’s
when needed.
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Decimals
Addition & Subtraction
MNU 3-03a
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Example : 3.2 + 0.487 + 5.73
3.200
0.487
5.730
9.417
1 11
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Keep point in
line
Decimals
Addition & Subtraction
MNU 3-03a
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Example : 6.2 – 3.19 + 1.783
6.200
+1.783
7.983
3.190
4.793
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Add first
Then subtract
Decimals
Addition & Subtraction
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MNU 3-03a
Now try Exercise 2
Ch13 (page 58)
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Starter Questions
MNU 3-03a
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1. (-5) - (-6) + 11
2. Calculate 15% of 60
3. What is the perimeter and area
of a square with length 4cm.
4. Find the value of x
3x - 9 = 27
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Decimals
Simple Multiplication
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MNU 3-03a
Learning Intention
1. We are learning to do simple
decimal multiplication.
Success Criteria
1. Apply rules to do simple
multiplication.
2. Show clear working.
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Decimals
Simple Multiplication
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MNU 3-03a
Example 1 : 0.6 x 0.4
6 x 4 = 24
0. 24
2 digits after
decimal place
Example 2 : 0.09 x 0.3
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9 x 3 = 27
0. 027
3 digits after
place
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Dept.
Decimals
Simple Multiplication
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MNU 3-03a
Example 3 : 0.071 x 0.5
71 x 5 = 355
4 digits after
decimal place
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0. 0355
Decimals
Simple Multiplication
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MNU 3-03a
Now try Exercise 5
Ch13 (page 62)
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Starter Questions
MNU 3-03a
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1.
2.
3.
Simplfy the ratio
57 : 19
1
How many degrees in an
of a circle
8
I got $250 for £100. How much would I
get for £1.
4.
Put in order, smallest first.
0.05, 0.21, 0.01, 0.026
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Decimals
Division of a Decimal
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MNU 3-03a
Learning Intention
1. We are learning to divide
simple decimal numbers.
Success Criteria
1. Understand simple rule
for dividing decimals.
2. Apply them to simple
calculations.
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Decimals
Division of a Decimal
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MNU 3-03a
Do not attempt to divide by a decimal,
multiply the divisor so it is a whole number first.
Example 1 : 3.5 ÷ 0.7
35 ÷ 7 = 5
x 10
x 10
Example 2 : 0.8 ÷ 0.2
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8÷2= 4
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Decimals
Division of a Decimal
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MNU 3-03a
Do not attempt to divide by a decimal,
multiply the divisor so it is a whole number first.
Example 3 : 0.036 ÷ 0.04
3.6 ÷ 4 = 0.9
x 100
Example 4 : 24 ÷ 3000
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24 ÷ 3÷1000 = 0.008
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Decimals
Division of a Decimal
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MNU 3-03a
Now try Exercise 6
Ch13 (page 63)
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Starter Questions
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MNU 3-03a
The answer to the question is
60
Write down as many questions as you can
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Decimals
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MNU 3-03a
Rounding to Any Number of Decimal Places
Learning Intention
1. We are learning to round to
any number of decimal
places.
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Success Criteria
1. Use previous knowledge to
help round to any number
of decimal places.
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Decimals
MNU 3-03a
Rounding to Any Number of Decimal Places
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When rounding to :
1 decimal place look at 2nd decimal figure
e.g. 2.46
2 decimal place look at 3rd decimal figure e.g. 6.456
3 decimal place look at 4th decimal figure
e.g. 3.7846
4 decimal place look at 5th decimal figure
e.g. 13.1146
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Decimals
MNU 3-03a
Rounding to Any Number of Decimal Places
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Example : The number 4.2615937
Rounded to 1 decimal place, the number is 4.3
Rounded to 2 decimal place, the number is 4.26
Rounded to 3 decimal place, the number is 4.262
Rounded to 4 decimal place, the number is 4.2616
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Decimals
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MNU 3-03a
Rounding to Any Number of Decimal Places
Now try Exercise 7
Ch13 (page 64)
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Starter Questions
MNU 3-03a
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Q1.
Round the following to 2 decimals places.
(a) 3.5647
(b) 4.55732
(c) 3.98111
Q2. Write in standard form.
(a) 12300 (b) 0.0034 (c) 0.0005
Q3.
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Expand out 4h(h 2  2h  3)
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Significant Numbers
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MNU 3-03a
Learning Intention
1. We are learning about the
term significant figure.
Success Criteria
1. Understand what the
term significant figure
means.
2. Apply knowledge to
problems.
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Significant Numbers
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MNU 3-03a
In mathematics a figure or digit is significant
if it gives an idea of both:
(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
Has 3 significant figures.
50.6 cm Has 3 significant figures.
0.506 cm Has 3 significant figures.
0.00506 cm Has 3 significant figures.
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Significant Numbers
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MNU 3-03a
IMPORTANT : When dealing with WHOLE NUMBERS you need
More information before you can tell if trailing zero’s are significant.
Question ? How many significant figures is this number to.
360
Is it 2 or 3 !!!
3
If I said 359 to the nearest ten is 360. How many significant figures. 2
If I said there are 360 deg. in a circle. How many significant figures.
YOU NEED TO KNOW THE CONTEXT OF THE QUESTION WHEN
DEALING WITH WHOLE NUMBERS WITH TRAILING ZEROS.
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WORK OUT WHAT THE ZERO MEANS
Significant Figures
Decimals
0.001090
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MNU 3-03a
To the left of
The number
Middle of
the number
To the right of
the number
Always Significant
Not Significant
Always Significant
Whole Numbers
03060
To the left of
The number
Middle of
the number
? Depends
More Info.
Not Significant Always Significant Read Question
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Significant Numbers
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MNU 3-03a
Now try Ex 8
Ch13 (page 65)
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Starter Questions
MNU 3-03a
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Q1. 0.5 + 5 x 8
Q2. Multiply out the brackets
(a)
2 - 6(x - 3)
Q3. Find g when
(b)
(x - 4)( 3x + 5)
7 - g  32
Q4. If a  7, b  6, c  3
Find
ac2  b 2
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Profit and Loss
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MNU 3-03a
Learning Intention
1. We are learning the
terms profit and loss.
Success Criteria
1. Understand the terms
PROFIT and LOSS.
2. Apply knowledge to
calculations. In context.
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Profit and Loss
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MNU 3-03a
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.
LOSS = Buying Price – Selling Price
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Profit and Loss
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MNU 3-03a
Example 1
If I buy a Playstation for £100 and sell it for £120.
I have made a PROFIT of £120-£100 = £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
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£5.50 - £4.00 = £1.50
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Profit and Loss
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MNU 3-03a
Now try Ex 9
Ch13 (page 67)
Q1 – Q3
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Hire Purchase
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MNU 3-03a
Learning Intention
1. We are learning the
the meaning of the term
Hire Purchase.
Success Criteria
1. To know the meaning of the
term HIRE PURCHASE.
2. Apply the process of working
out the Hire Purchase for
everyday products.
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Starter Questions
MNU 3-03a
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Q1. Expand out 2j (k – 5g + 4jk)
Q2. Find all the missing angles
Q3.Find m when
55 = 13 - 14m
Q4. If a  9, b  7, c  4
Find
ab  c 2
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25o
Hire Purchase
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MNU 3-03a
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.
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Hire Purchase
MNU 3-03a
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Buying Products
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 = £420.60 - £365.50 = £55.10
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Hire Purchase
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MNU 3-03a
Now try Ex 9
Ch13 (page 68)
Q4 – Q7
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Starter Questions
MNU 3-03a
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Q1. Expand out 2a (a – c + 4ab)
Q2. Find the missing angle
Q3. Find g when
7 - 8g  95
Q4. If a  9, b  7, c  4
Find
ab  c 2
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22o
Salaries & Overtime
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MNU 3-03a
Learning Intention
1. We are learning to
calculate Salaries and
Overtime.
Success Criteria
1. To know the meaning of the
terms Salary and Overtime.
2. Apply knowledge to
calculations. In context.
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Salaries & Overtime
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MNU 3-03a
Salary :
How much a person is paid to do a job.
Can be measured weekly, monthly or
annually.
Overtime :
Extra work outside normal work time.
Usually at night or weekends.
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Salaries & Overtime
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MNU 3-03a
Example 1 :
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
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Salaries & Overtime
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MNU 3-03a
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
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Salaries & Overtime
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MNU 3-03a
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
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Salaries & Overtime
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Level F
Now try Ex 9
Ch13 (page 68)
Q8 – Q14
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Starter Questions
MNU 3-03a
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Q1. Expand out 2a (a – c + 4ab)
Q2. Find two missing angles
32o
Q3. Find y
1
y =100
5
Q4. The answer is 45. What is the queston.
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Foreign Exchange
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MNU 3-03a
Learning Intention
1. We are learning to
convert £’s to another
currency and vice versa.
Success Criteria
1. Understand the term
exchange rate and be apply it
to convert £’s to another
currency.
2. Be able to convert back to £’s.
3. Show clear working.
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Foreign Exchange
MNU 3-03a
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Think The currency in most of Europe is the euro €
going on
The exchange rate is approximately
holiday !
£1

1.54 €
Converting £’s to Euros € simply multiply
(a)
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To change £80 to euros
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80 x 1.54 = 123.20 €
Foreign Exchange
MNU 3-03a
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Coming back from holiday we want to do the opposite
i.e. euros to £’s
Think
The exchange rate is approximately
back from
£1 
1.54 €
holiday !
Converting Euros €’s to £’s simply divide
To change 616 € to £’s
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616 ÷ 1.54 = £400
Foreign Exchange
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MNU 3-03a
Now try Ex 9
Ch13 (page 70)
Q15 – Q20
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