maths and graphs for biologists l.o:to use ratios, calculate percentage increase and percentage...

Maths and Graphs Maths and Graphs for Biologistsfor BiologistsL.O: to use ratios, calculate percentage

increase and percentage decrease

to improve graph vocabulary

Starter: We require a GCSE Maths grade B for Biology A Level… so why might you need good maths skills in Biology?

Using RatiosUsing RatiosWhy?Why?

How?How?

Using RatiosUsing RatiosWhy?Why?

Used for calculating proportions, e.g. sufferers of Cystic Fibrosis are more frequently female than male, in a ratio of 2:1

Using RatiosUsing RatiosWhy?Why? Used for calculating proportions, e.g. sufferers

of Cystic Fibrosis are more frequently female than male, in a ratio of 2:1. Population size = 200,000

How?How? Step 1: Add the ratio together (x) (2 + 1 = 3) Step 2: Divide the population size by x

(200,000 / 3 = 66666) Step 3: Multiply by the part of the ratio you

are interested in (66666 x 2 = 13,3333)

Percentage IncreasePercentage Increase

Why?Why?

How?How?

Percentage IncreasePercentage IncreaseWhy?Why?

Used to calculate the rise of diseases in populations, the effectiveness of medicines… etc… E.g. TB deaths in 1986 = 50,000 and rose to 86,000 in 2003. What is the % increase?

Percentage IncreasePercentage IncreaseWhy?Why?Used to calculate the rise of diseases in populations,

the effectiveness of medicines… etc… E.g. TB deaths in 1986 = 50,000 and rose to 86,000 in 2003. What is the % increase?

How?How?Step 1: Find the two values ‘new’ and ‘old’ (86000 and

50000)Step 2: Find the difference between these two values

(86,000 – 50,000 = 36,000)Step 3: Divide by the ‘old’ value (36000/50000 – 0.72)Step 4: Multiply by 100 and remember to your units! (0.72 x 100 = 72%)

Percentage DecreasePercentage DecreaseWhy?Why?

How? How?

Percentage DecreasePercentage DecreaseWhy?Why?

Used to calculate the effectiveness of a medicine, the decline in disease, loss of white blood cells, red blood cells…etc!

How? How?

Step 1: Find the two values ‘old’ and ‘new’

Step 2: Find the difference between these values

Step 3: Divide by the ‘old’ value

Step 4: Multiply by 100 & remember your units! %

Exam Examples!Exam Examples!

Solve the past exam questions on the sheet provided…

Your knowledge of the topic is not required, just your mega maths skills!

Remember to ask for help

5a Answers5a AnswersStanding up/fastest rate: 22.8

Sat down : 14.1

22.8 - 14.1 = 8.7

8.7 / 14.1 = 0.617

0.617 x 100

Answer = 61.7 / 62%

5b Answers5b Answers118 – 30 = 88

88 / 118 = 0.7457

0.7457 x 100

Answer = 74.5 %

5c Answers5c Answers‘old’/january = 1,800 ‘new’/august = 5,800

5800 – 1800 = 4000

4000 / 1800 = 2.222

2.222 x 100 = 222

Answer = 222%

15 Answers15 Answers‘old’/sea level: 5.1 ‘new’/above sea level: 6.5

6.5 – 5.1 = 1.4

1.4 / 5.1 = 0.2745

0.2745 x 100 = 27.45

Answer = 27.5%

4ci Answers4ci Answers‘old’/1997: 20,000 ‘new’/2006: 33,500

33,500 – 20,000 = 13,500

13,500 / 20,000 = 0.675

0.675 x 100

Answer = 67.5%

6aii Answers6aii AnswersAdd the ratio 1.5 + 1 = 2.5

Divide popn size 60,000 by 2.5 = 24,000

Multiply by 1.5 (24,000 x 1.5)

Answer = 36,000

10ciii Answers10ciii Answers‘old’/1996: 9 ‘new’/2006: 14

14 – 9 = 5

5 / 9 = 0.5556

0.5556 x 100 = 55.56

Answer = 55.56%

Command WordsCommand WordsMatch up the command word to the correct explanation

Analyse Clarify a concept or explain it, indicating how it relates to some other way of looking at things.

Compare

Use words to say how something looks and use DATA! (say what you see in detail, no scientific explanation!)

Describe

Say what you think will happen based on your knowledge and using information you have been given.

Explain

This only needs to be a short answer without explanation.

Interpret

There may be a variety of acceptable answers rather than just one. You may need to apply scientific knowledge and/or principles in an unfamiliar context.

Name / state / give

Take apart a concept or a process, and explain it step by step.

Predict

State the similarities and the differences between two or more things.

Suggest

Write a biological reason to say why something is or why something has happened.

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Graph Verbs!

• Split half a page of your notes into two columns.

• At the top of one column write ‘up’ and at the top of the other column write ‘down’.

‘Up’

‘Down’

Graph Adverbs!• Adjective (describing word) + verb (‘doing’

word / action) = adverb!

• http://www.bbc.co.uk/skillswise/video/adverbs

Application of Knowledge