How to Answer Trace Table Questions (OCR GCSE Computer Science): Revision Note

Complete

Fill in the table with correct values

State

Give the value/output/result (usually a single word or number)

Explain

Say why something happens or changes in the program

Identify

Spot where something goes wrong or doesn't match expectations

This algorithm calculates the number of points a student gets for the distance they throw in the javelin:

01 javelinThrow = input("Enter distance")
02 yearGroup = input("Enter year group")
03 if javelinThrow >= 20.0 then
04     score = 3
05 elseif javelinThrow >= 10.0 then
06     score = 2
07 else
08     score = 1
09 endif
10 if yearGroup != 11 then
11     score = score * 2
12 endif
13 print("The score is", score)

Complete the trace table for the algorithm when a student in year 10 throws a distance of 14.3

You may not need to use all the rows in the table

1. Read the code carefully

• Line 1: It asks you to type in the javelin distance and stores it in a variable called javelinThrow

• Line 2: It asks for your year group (like "10" or "11") and stores it in yearGroup

• Lines 3–9: It decides how many points to give you:

  • If your throw was 20 metres or more, you get 3 points

  • If your throw was 10 metres or more, you get 2 points

  • If your throw was less than 10 metres, you get 1 point

• Lines 10–12: It checks if you are not in Year 11:

  • If you're not in Year 11, your score is doubled

  • If you are in Year 11, your score stays the same

• Line 13: It prints your final score

2. Use the trace table provided

• The trace table contains six blank lines which give you an indication of how many times a change/output is required

• If you get to the end and you have only completed 2/3 lines, check again, something is probably wrong

3. Work line by line

01 javelinThrow = input("Enter distance")

14.3

02 yearGroup = input("Enter year group")

10

03 if javelinThrow >= 20.0 then

No

04     score = 3

05 elseif javelinThrow >= 10.0 then

Yes

06     score = 2

score = 2

4. Watch out for variable resets

• This program contains no loops

5. Show the final output clearly

13 print("The score is", score)

The score is 4

Final answer