Week 3 Understanding and using numbers MATHS Week 3 Understanding and using numbers
To warm up……. Can you answer all 10 questions on this weeks number?
What are we going to do today? Recap from last week Understand and use very large numbers Use and calculate with the 4 operations - +, -, x and ÷ Identify Prime numbers Factors Multiples Powers and roots – squares, cubes, square roots, cube roots Highest common factor Lowest common multiple from lists of numbers Follow BIDMAS – the order of operations
For today…
What did we do last week?
Why are they misleading? Misleading graphs Why are they misleading?
True or False: Sales are rising rapidly! 4370 4360 4350 4340 Sales 4330 4320 The graph is misleading because it suggests that sales have increased significantly over a five year period. In reality they have only increased by 70 units, which is not much given that they are selling thousands. 4310 4300 2000 2001 2002 2003 2004 2005 Year
This may help to explain the previous slide
Although the vertical scale starts at 0, it does not go up in even steps. This distorts the graph, and makes it look as though the biggest jump is between 1 and 2, rather than 3 and 4. Also, there are no labels on the axes, so we have no idea what this graph represents!
On this pictogram, there is no category for people who do not own a pet. The pictures are different sizes, and it appears that more people own a horse than any other animal. An improvement would be to redraw the pictogram, with each of the animals the same size and aligned with one another.
True or False: There are more 15 year old boys than girls. 18 year olds 18 year olds 15 year olds 15 year olds 17 year olds 17 year olds 16 year olds False. We cannot make this conclusion from these graphs because we don’t know the totals. There might be 10 boys in total, making roughly 5 aged 15, but 100 girls, 30 of which are 15. It only tells us the proportion of 15 year olds. 16 year olds
Summary of points Scale doesn’t start at zero Scale made very small to make graph look very big Scale values or labels missing from the graph Information missing from a pie chart Incorrect scale placed on the graph Size of images used in pictograms are different for the different categories
Here are some annual salaries Here are some annual salaries. Write them out in order from largest to smallest. Can you say the figures in words? (talk about place value) £25,740,030 £51,931,640 £40,100,000 £51,750,000 £34,621,093 £9,600,000 £149,440 £143,789 £25,216,800 £27,847,401 £0 £43,500,000
The order should look like this: £51,931,640 £51,750,000 £43,500,00 £40,100,000 £34,621,093 £27,847,401 £25,740,030 £25,216,800 £9,600,000 £149,440 £143,789 £0
Who am I? Write down the name of the celebrity next to the amount of money you think they earn in a year. Good luck! (Source: www.wageindicator.co.uk)
Who am I? How much money do I earn per year? Usain Bolt
Who am I? How much money do I earn per year? Theresa May
Who am I? How much money do I earn per year? Boris Johnson
Who am I? How much money do I earn per year? Lewis Hamilton
Who am I? How much money do I earn per year? Adele
Who am I? How much money do I earn per year? Jeremy Clarkson
Who am I? How much money do I earn per year? Daniel Radcliffe
Who am I? How much money do I earn per year? Pope Francis
Who am I? How much money do I earn per year? Queen Elizabeth II
Who am I? How much money do I earn per year? Jose Mourinho
Who am I? How much money do I earn per year? Ed Sheeran
Who am I? How much money do I earn per year? Simon Cowell
The wealthiest is…. correct them as you go
The wealthiest is…. £51,931,640
Next wealthiest is…. £51,750,000
Next wealthiest is…. £43,500,000
Next wealthiest is…. £40,100,000
Next wealthiest is…. £34,621,093
Next wealthiest is.… £27,847,401
Next wealthiest is…. £25,740,030
Next wealthiest is…. £25,216,800
Next wealthiest is…. £9,600,000
Next wealthiest is…. £149,440
Next wealthiest is…. £143,789
And the least wealthy is…. £0
The order should look like this: Adele £51,931,640 Daniel Radcliffe £51,750,000 Simon Cowell £43,500,00 The Queen £40,100,000 Lewis Hamilton £34,621,093 Ed Sheeran £27,847,401 Usain Bolt £25,740,030 Jose Mourinho £25,216,800 Jeremy Clarkson £9,600,000 Theresa May £149,440 Boris Johnson £143,789 The Pope £0
Inequality symbols An inequality shows that two values are not equal. A < B says that A is less than B A > B says that A is greater than B
Use your amounts of money and your T/F card True or False? Use your amounts of money and your T/F card
Usain Bolt’s salary > The Queen’s salary True or False? Usain Bolt’s salary > The Queen’s salary
Lewis Hamilton’s salary > Jeremy Clarkson’s salary True or False? Lewis Hamilton’s salary > Jeremy Clarkson’s salary
Theresa May’s salary > The Pope’s salary True or False? Theresa May’s salary > The Pope’s salary
Simon Cowell’s salary > Adele’s salary True or False? Simon Cowell’s salary > Adele’s salary
True or False? 574 > 121
True or False? 1249 < 578
Number of days in a week > Number of sides of a nonagon True or False? Number of days in a week > Number of sides of a nonagon
Number of days in February < Number of days in October True or False? Number of days in February < Number of days in October
Number of degrees in a circle < Number of months in a year True or False? Number of degrees in a circle < Number of months in a year
True or False? Number of planets in the solar system > Number of blind mice in the nursery rhyme
Number of Olympic rings > Number of days of Christmas True or False? Number of Olympic rings > Number of days of Christmas
Addition & Subtraction Do you all have a method for adding and subtraction WITHOUT a calculator?
Addition 97 + 96 157 + 368 875 + 326
Subtraction 76 – 23 102 – 78 1016 - 358
Multiplication Which method do you use?
3 x 7 12 x 7
45 x 7
468 x 8
39 x 47
156 x 17
41.9 x 8 41.9 x 0.8 41.9 x 0.08
2.5 x 4.5 Extension: 0.58 x 126
Division
375 ÷ 2
2793 ÷ 4
591623 ÷ 8
746 ÷ 3
Word of the day - integer What is an integer? An integer is a positive or negative whole number, including zero.
+, -, x, ÷ positive and negative integers
Multiplication 4 x 5 -4 x 5 -4 x -5
Divide 20 ÷ 5 20 ÷ -5 -20 ÷ -5
Addition 4 + -6 -4 + 6 -4 + -6
Subtraction 10 - -2 -10 – 2 -10 - -2
Negative Number BINGO
Put one number in each box Put one number in each box. Pick any numbers from the list but no repeats. 15 -10 3 -21 -13 17 -9 11 18 -12 -15 -2 -4 22 6 25 7 20 -5 24 16 14 8 -3
8 -12
10 - -12
- 2 + 8
20 - -5
- 1 +8
-2 x -10
-2 -3
20 - -4
- 4 x -4
15 + -1
9 – 1
7 -10
16 + -1
-40 ÷ 4
-9 ÷ -3
7 x -3
-26 ÷ 2
-17 x -1
3 x -3
12 + -1
15 - -3
6 x -2
- 20 + 5
10 - 12
What is the answer to this question? 2 + 3 x 4
3 + 7 x 6 – 5
Bidmas activity:
Factors, Multiples and Primes
What is a …….. Factor Multiple Prime
Prime Numbers A prime number has exactly two factors – one and itself One is not a prime number because it has only one factor – itself Two is the first prime number Two is the only even prime number
Give an example of as many of these as possible Give an example of as many of these as possible. Then put it away - we will revisit this before the end of the lesson. A factor of 24 A multiple of 5 A prime number A power of 2 A square number A cube number The square root of 100 The cube root of 27
http://www.visnos.com/demos/sieve-of-eratosthenes
On your number grid, cross out the 5 times table, apart from the number 5.
Cross out the 6 times table, apart from the number 6.
What are we left with? What about the number 1? Cross out the 2 times table, apart from the number 2. Cross out the 3 times table, apart from the number 3. What are we left with? What about the number 1?
What is a …….. Factor Multiple Prime
Question For each of these pairs of numbers, there is just one prime number that lies between them. In each case, write that prime number. a) 8 12 b) 14 18 c) 25 30 20 28 e) 32 40 f) 44 52 g) 54 60 h) 38 42
Factors multiples puzzle
Answers
From these numbers: 1 3 8 12 16 20 13 15 2 17 24 6 Write down 1 3 8 12 16 20 13 15 2 17 24 6 Write down 4 prime numbers all the factors of 6 any multiples of 4
Square numbers √ Square Square root Square Square root Area = 3 x 3 = 3² 3 9 =9 Square root √ Area = 4 x 4 Square = 4² 4 16 Square root = 16
cube numbers cube cube Cube root Cube root Volume = 3 x 3 x 3 Volume = = 3³ = 4³ cube = 27 cube = 64 4 64 3 27 Cube root Cube root
Can you answer these questions? What is the square of 5? What is the square root of 36? Is there another one? What is the cube of 2? What is the cube root of 125? What are the powers of 10?
From these numbers: 121 49 20 19 800 1000 5 Find two square numbers 121 49 20 19 800 1000 5 Find two square numbers a cube number the square root of 400 the cube root of 125
90 Prime factors Then with powers Over to you – prime factors of 84?
84
Finally - Factors, Multiples and Primes 8 quick questions Write down your answers
1 Which of the following numbers divides into 49, without remainder? Divisors a: 3 b: 4 c: 7 d: 9
2 Including one and itself, how many factors has the number 6? Factors a: 2 b: 3 c: 4 d: 6
3 Which of the following is a multiple of 6? Multiples a: 1 b: 3 c: 9 d: 12
4 Common Factors a: 2 b: 4 c: 8 d: 36 Which of the following is a common factor of 12 and 18? Common Factors a: 2 b: 4 c: 8 d: 36
5 Prime Numbers a: 2 b: 15 c: 17 d: 29 Which of the following is not a prime number? Prime Numbers a: 2 b: 15 c: 17 d: 29
6 Prime Numbers a: 51 b: 53 c: 55 d: 57 What is the next prime number after 47? Prime Numbers a: 51 b: 53 c: 55 d: 57
7 Prime Factor Decomposition a: 2 x 15 b: 3 x 10 c: 5 x 6 d: 2 x 3 x 5 Which of the following shows the prime factors of 30? Prime Factor Decomposition a: 2 x 15 b: 3 x 10 c: 5 x 6 d: 2 x 3 x 5
8 Prime factor decomposition a: 23 x 5 b: 22 x 10 c: 2 x 4 x 5 Which of the following shows the prime factors of 40 (with powers)? Prime factor decomposition a: 23 x 5 b: 22 x 10 c: 2 x 4 x 5 d: 4 x 10
Answers
1 Which of the following numbers divides into 49, without remainder? Divisors a: 3 b: 4 c: 7 d: 9
2 Including one and itself, how many factors has the number 6? Factors a: 2 b: 3 c: 4 d: 6
3 Which of the following is a multiple of 6? Multiples a: 1 b: 3 c: 9 d: 12
4 Common Factors a: 2 b: 4 c: 8 d: 36 Which of the following is a common factor of 12 and 18? Common Factors a: 2 b: 4 c: 8 d: 36
5 Prime Numbers a: 2 b: 15 c: 17 d: 29 Which of the following is not a prime number? Prime Numbers a: 2 b: 15 c: 17 d: 29
6 Prime Numbers a: 51 b: 53 c: 55 d: 57 What is the next prime number after 47? Prime Numbers a: 51 b: 53 c: 55 d: 57
7 Prime Factor Decomposition a: 2 x 15 b: 3 x 10 c: 5 x 6 d: 2 x 3 x 5 Which of the following shows the prime factors of 30? Prime Factor Decomposition a: 2 x 15 b: 3 x 10 c: 5 x 6 d: 2 x 3 x 5
8 Prime factor decomposition a: 23 x 5 b: 22 x 10 c: 2 x 4 x 5 Which of the following shows the prime factors of 40 (with powers)? Prime factor decomposition a: 23 x 5 b: 22 x 10 c: 2 x 4 x 5 d: 4 x 10
Add them up! 7 or 8? Brilliant 5 or 6? Jolly good show 3 or 4? Some good, but revision needed 1 or 2? Oh dear, have you been paying attention? 0 Whoops!
Plenary - revisit this: can you answer all these now? A factor of 24 A multiple of 5 A prime number A power of 2 A square number A cube number The square root of 100 The cube root of 27
Website of the week Help is at hand https://www.bbc.co.uk/education/examspecs/z8sg6fr
Homework AQA Number Homework sheet