25112020 Stem and leaf L O To be

25/11/2020 Stem and leaf L. O. To be able to § Draw a stem and leaf diagram from a list of data § Use a stem and leaf diagram to interpret data Key Words stem, leaf, key, discrete, averages, data Starter MATHSWATCH CLIP GRADE

25/11/2020 Stem and leaf MATHSWATCH CLIP GRADE CONTENTS – Click to go to… DRAWING STEM AND LEAF USING STEM AND LEAF

25/11/2020 Stem and leaf MATHSWATCH CLIP GRADE DRAWING A STEM AND LEAF

25/11/2020 Stem and leaf MATHSWATCH CLIP GRADE A stem and leaf diagram show ordered discrete data. Each number is broken up into two parts. For example, you might split the number 23 into a stem of 2 and a leaf of 3 Your key would look like this. . . Key: 2 3 = 23 So the stem tells us how many tens and the leaf tells us the units of each data value

25/11/2020 Stem and leaf MATHSWATCH CLIP GRADE

25/11/2020 Stem and leaf MATHSWATCH CLIP GRADE Stem and leaf § Data must be in order § Think about how you will split each number into a stem and a leaf § Put them into the diagram Ø Cross out each number as you add it Ø Space them out evenly § Don’t forget your KEY!

25/11/2020 Stem and leaf MATHSWATCH CLIP GRADE Example 7, 16, 37, 45, 22, 37, 11, 4, 35, 29, 33 Key: 2 2 = 22 Tens 0 1 2 3 4 4 1 2 3 5 7 6 9 5 7 7 Units

25/11/2020 Stem and leaf MATHSWATCH CLIP GRADE Task – on your mini whiteboards, draw a stem and leaf diagram for the following data 12, 25, 42, 7, 15, 24, 19, 5, 46, 38, 27, 3, 26, 45, 33, 27, 24

11/25/2020 Stem and leaf MATHSWATCH CLIP GRADE Stem-and-leaf diagrams are useful as they contain the same degree of accuracy as the original data.

25/11/2020 Stem and leaf MATHSWATCH CLIP GRADE Task – Put each set of data into a stem and leaf diagram 44, 39, 22, 29, 37, 21, 41, 30, 27, 42 2 1, 2, 7, 9 4 2, 7, 7 3 0, 0, 7, 9 5 0, 4, 4, 6, 7, 9, 9 4 1, 2, 4 6 0, 1, 3 73, 72, 90, 92, 78, 102, 99, 73, 90, 100 7 2, 3, 3, 8 8 9 54, 59, 61, 42, 50, 63, 47, 60, 59, 56, 57 0, 0, 2, 9 10 0, 2 9, 12, 3, 28, 3, 3, 3, 0, 11, 10, 5, 9, 29, 31, 1, 6 0 0, 1, 3, 3, 5, 6, 9, 9 1 0, 1, 2, 2 8, 9 3 1

25/11/2020 Stem and leaf MATHSWATCH CLIP GRADE Discussion – For the number below, can you think of how they could be represented on a stem and leaf? What would the key look like? Show me ideas on your mini whiteboards… a) 145 b) 1. 7

25/11/2020 Stem and leaf MATHSWATCH CLIP GRADE Task – draw a stem and leaf diagram to show one of these sets of data. Choose your level of challenge… Easy Medium Hard

25/11/2020 Stem and leaf MATHSWATCH CLIP GRADE Stem-and-leaf diagrams can be used to compare two sets of data. The back-to-back stem-and-leaf diagram shown below compares the height of 15 boys and 14 girls from a form group. A stem-and-leaf diagram comparing the heights of pupils in a form group The diagram shows that the boys in the form group are typically taller than the girls. The heights of the boys are also more varied than the girls’ heights.

25/11/2020 Stem and leaf MATHSWATCH CLIP GRADE USING A STEM AND LEAF

Stem and leaf 25/11/2020 MATHSWATCH CLIP GRADE We also need to be able to use a stem and leaf diagram to analyse the data that it represents. What information do you think we might be able to find out from a stem and leaf diagram? 2 3 4 5 1 4 2 0 9 2 6 5 7 7 7 6 9 4 Key: 2 1 = 2. 1

Stem and leaf 25/11/2020 Example 5|2 = 52 a) b) 4 0 4 7 9 5 2 3 4 7 7 8 9 9 6 1 1 3 3 4 5 5 8 8 9 7 0 0 4 5 6 8 0 1 1 Calculate the median. = 63 Calculate the range. MATHSWATCH CLIP GRADE

Stem and leaf 25/11/2020 Example 5|2 = 52 a) b) 4 0 4 7 9 5 2 3 4 7 7 8 9 9 6 1 1 3 3 4 5 5 8 8 9 7 0 0 4 5 6 8 0 1 1 Calculate the median. = 63 Calculate the range. = 81 - 40 = 41 MATHSWATCH CLIP GRADE

Stem and leaf 25/11/2020 2 3 4 5 1 4 2 0 2 6 9 5 7 7 7 6 9 9 4 MATHSWATCH CLIP GRADE Key: 2 1 = 2. 1 This stem and leaf diagram shows the heights, to the nearest metre, of a number of trees: ALL: How many trees were there in the sample? MOST: What is the range of heights of the trees? What is the modal height of tree? SOME: What is the median tree height?

25/11/2020 Stem and leaf MATHSWATCH CLIP GRADE Task 0 8 8 9 1 1 2 0 3 5 5 7 8 8 9 3 2 2 3 3 5 6 8 8 4 1 1 1 4 4 8 9 1 3 3 5 8 This stem and leaf diagram shows data about the areas of some photographs in an old album. Key 4 1 represents 41 cm a) Write down the number of photographs that have an area of 38 cm 2 b) What is the total number of photographs? c) Work out the range of the areas of the photographs d) What is the modal area of the photographs?

MATHSWATCH CLIP Stem and leaf 25/11/2020 GRADE Task - How confident do you feel drawing and using stem and leaf diagrams? Choose SUPPORT, CORE or EXTENSION from the available worksheets… 0 1 2 3 5 0 0 3 7 8 8 0 0 0 2 5 5 6 0 0 4 5 5 KEY 2 3 4 5 3 1 1 0 7 4 2 2 8 5 6 4 5 5 3 a) 15 b) 35 – 5 = 30 c) 13 times a) 41 b) 53 – 23 = 30 c) 12 teachers 0 1 2 3 4 1 2 3 KEY CLICK FOR SOLUTIONS… 1 2 4 6 6 1 3 3 5 5 5 8 9 9 2 2 4 5 5 8 8 9 0 5 6 KEY a) 19 b) 46 – 1 = 45 c) 2 sentences 8 8 9 1 1 2 2 4 4 8 9 0 1 2 3 a) 24 b) 33 – 18 = 15 c) 6/15 or 2/5 KEY

25/11/2020 Stem and leaf MATHSWATCH CLIP GRADE

25/11/2020 Exam question Stem and leaf MATHSWATCH CLIP GRADE

25/11/2020 Stem and leaf MATHSWATCH CLIP GRADE Spot the errors! 0 1 2 3 4 2 1 4 2 9 5 7 9 2 6 5 8 8 8 6 a) The range of the data is 40 b) The median of the data is 25 c) The mode of the data is 8