PAss Functional Skills

Tree diagrams

Tree diagrams for Functional Skills Biology: what it means, how to set the working out, and the questions it is asked in.
  • Functional Skills
  • Biology
  • Spec A13
  • 10 min read
  • 7 revision boxes

Introduction

2 boxes
3 min read

What is tree diagrams?

Listen to this box

Transcript

A short spoken summary of tree diagrams and where it is used.

A spoken walk-through of tree diagrams before you read the notes.
Practise the routine version until it is automatic, then move to the multi-step questions.
5 rows

The tree diagrams reference table

Sketch the shape even when the question does not ask for one — it makes the next step obvious.
Term
Meaning
Example
Row 1 column 1
Row 1 column 2
≈160\approx 160
Row 2 column 1
Row 2 column 2
×10\times 10 moves every digit one column left
Row 3 column 1
Row 3 column 2
≈160\approx 160

Learning

3 boxes
5 steps

How to work with tree diagrams

This idea appears again in the higher-mark questions, so it is worth over-learning.
The layout below is the one the mark scheme expects.

Diagram showing tree diagrams laid out step by step

The same idea drawn out, so the method is visible.
  1. Read the question and write down what is being asked for.
  2. Set out the working for tree diagrams in the order the method gives.
  3. Substitute the values and simplify.
Start from the definition and substitute the numbers the question gives you.
Simplify one line at a time: 34×25\frac{3}{4} \times \frac{2}{5}.
Answer: 34×25\frac{3}{4} \times \frac{2}{5}
3 rules

Key facts: Tree diagrams

The examiner marks the working, so a correct answer with no method still drops marks.
The layout below is the one the mark scheme expects.

Diagram showing tree diagrams laid out step by step

The same idea drawn out, so the method is visible.

  • Rule 1

    How tree diagrams behaves in the 1st of the cases the specification names.
    ≈160\approx 160

  • Rule 2

    How tree diagrams behaves in the 2nd of the cases the specification names.
    x2+5x+6=0x^2 + 5x + 6 = 0
5 steps

How to work with tree diagrams

Practise the routine version until it is automatic, then move to the multi-step questions.
  1. Read the question and write down what is being asked for.
  2. Set out the working for tree diagrams in the order the method gives.
  3. Substitute the values and simplify.
  4. Check the answer against an estimate before writing it down.
Start from the definition and substitute the numbers the question gives you.
Simplify one line at a time: ≈160\approx 160.
Answer: 49=7\sqrt{49} = 7

20 minutes

Get your predicted grade

Twenty questions gives you a predicted grade, your target, and the gap between them — plus the topics that close it fastest.
Get my predicted grade

Examples

2 boxes
1 marks · worked

Worked example: tree diagrams

Practise the routine version until it is automatic, then move to the multi-step questions.
2 marks · worked

Practice question 7: a2+b2=c2a^2 + b^2 = c^2

Sketch the shape even when the question does not ask for one — it makes the next step obvious.
The layout below is the one the mark scheme expects.

Diagram showing tree diagrams laid out step by step

The same idea drawn out, so the method is visible.
Worth knowing: ≈160\approx 160.

Practice bank

Thousands of revision questions

Every topic is backed by graded practice with instant marking and full solutions.
Try it now
Practice questions
3,000+
Topics
10
Marking and solutions
Instant

Common questions

How many marks is tree diagrams usually worth?
Between one and four, depending on how many steps the question asks for.
Is this on the Functional Skills Biology paper?
Yes — it sits in the Markets and demand strand.