Lesson 6 Stem and Leaf and Scattergraphs..Mathswatch 89/87.

GCSE Maths Starter 6

2. Simplify 3a + 2b + 5a – 7b3. Simplify x⁸ ÷ x²4. What is 354 ÷ 6

5. Copy the shape below into your exercise books and draw 5 more shapes that tessellate with it.

1) Reflect the shape below in the y axis.

• To put raw data into a stem and leaf diagram.• To interpret stem and leaf diagrams.• To Complete scatter graphs and describe the

relationship/correlation.EXTN: To make predications using a scatter graphs. (Grade C)

Lesson 6 Stem and Leaf and Scattergraphs..Mathswatch 89/87.

How to Draw One:

1. Put the first digits of each piece of data in numerical order down the left-hand side

2. Go through each piece of data in turn and put the remaining digits in the proper row

3. Re-draw the diagram putting the pieces of data in the right order

4. Add a key

Lesson 6 Stem and Leaf and Scattergraphs.

Mathswatch 89/87.

Here are the marks gained by 30 students in an examination:

63 58 61 52 59 65 69 75 70 54 57 63 76 81 64

68 59 40 65 74 80 44 47 53 70 81 68 49 57 61

Write the tens figures in the left hand column of a diagram.

These are the ‘STEMS’

4 56 7 8

Lesson 6 Stem and Leaf and Scattergraphs.

Mathswatch 89/87.

Here are the marks gained by 30 students in an examination:

63 58 61 52 59 65 69 75 70 54 57 63 76 81 64

68 59 40 65 74 80 44 47 53 70 81 68 49 57 61

4 56 7 8

Go through the marks in turn and put in the units figures of each mark in the proper row. These are the ‘LEAVES’

3

8

1

Lesson 6 Stem and Leaf and Scattergraphs.

Mathswatch 89/87.

Here are the marks gained by 30 students in an examination:

63 58 61 52 59 65 69 75 70 54 57 63 76 81 64

68 59 40 65 74 80 44 47 53 70 81 68 49 57 61

4 56 7 8

When all the marks are entered the diagram will look like this:

3

8

1

0 4 7 92 9 4 7 9 3 7

5 9 3 4 8 5 8 15 0 6 4 0

1 0 1

Lesson 6 Stem and Leaf and Scattergraphs.

Mathswatch 89/87.

Here are the marks gained by 30 students in an examination:

63 58 61 52 59 65 69 75 70 54 57 63 76 81 64

68 59 40 65 74 80 44 47 53 70 81 68 49 57 61 4

56 7 8

Rewrite the diagram so that the units figures in each row are in order:

0 4 7 92 3 4 7 7 8 9 91 1 3 3 4 5 5 8 8 90 0 4 5 60 1 1

Lesson 6 Stem and Leaf and Scattergraphs.

Mathswatch 89/87.

Now……

4 56 7 8

Add a KEY:0 4 7 92 3 4 7 7 8 9 91 1 3 3 4 5 5 8 8 90 0 4 5 60 1 1

5|2 = 52

Lesson 6 Stem and Leaf and Scattergraphs.

Mathswatch 89/87.

Remember: - Always put in a Key- Always put your data in Order

Median:- to work out the median, you must find the middle value- if there are two middle values, you need the average

Range:- to work out the Range, subtract the smallest number from the biggest

Lesson 6 Stem and Leaf and Scattergraphs.

Mathswatch 89/87.

Stem and Leaf For You To Try…The stem & leaf diagram below shows the masses in kg of some people

in a lift.(a) How many people were weighed?(b) What is the range of the masses?(c) Find the median mass.

Stem Leaf345678

1 43 3 60 3 4 812 2 71 6

2

tens units

(a) 16 people.

(b) 86 – 31 = 55 kg

Median is the mean of the

8th and 9th data values.

(c) 56 kg

Lesson 6 Stem and Leaf and Scattergraphs.

Mathswatch 89/87.One For you

You can draw a line of best fit on Data

A line of best fit roughly follows the pattern of the points It does NOT have to go through any points or start on the

axes…

Positive Correlation

As one value increases, the

other increases

Negative Correlation

As one value increases, the other

decreases

No Correlation There is no pattern

in the data (and therefore no line of

best fit…)

Lesson 6 Stem and Leaf

and Scattergraphs.Mathswatch 89/87.

Lesson 6 Stem and Leaf

and Scattergraphs.Mathswatch 89/87.

• To put raw data into a stem and leaf diagram.• To interpret stem and leaf diagrams.• To Complete scatter graphs and describe the

relationship/correlation.EXTN: To make predications using a scatter graphs. (Grade C)

Lesson 6 Stem and Leaf and Scattergraphs..Mathswatch 89/87.