Trace a program one assignment at a time

UNDERSTAND · PRACTISE · REVIEW

A variable can change during execution. Write a trace table with one row per operation. Read assignment as updating a value, not as a mathematical equation that must stay true forever.

A worked example

Try this learning routine

1. Read the explanation and say the idea in your own words.
2. Cover the worked answer and attempt a similar question.
3. Check each step, including units or word meaning.
4. Record one mistake and retry a new example later.

Independent practice

Choose one answer for each question and write a reason. These are foundation activities, not a complete board examination.

1. Pseudocode: x ← 1; x ← x + 4; output x. What is output?

   • 2
   • 5
   • 1
   • 4

2. Pseudocode: x ← 2; x ← x + 4; output x. What is output?

   • 6
   • 2
   • 3
   • 5

3. Pseudocode: x ← 3; x ← x + 4; output x. What is output?

   • 7
   • 3
   • 6
   • 4

4. Pseudocode: x ← 4; x ← x + 4; output x. What is output?

   • 7
   • 5
   • 8
   • 4

5. Pseudocode: x ← 5; x ← x + 4; output x. What is output?

   • 9
   • 6
   • 5
   • 8

6. Pseudocode: x ← 6; x ← x + 4; output x. What is output?

   • 9
   • 7
   • 6
   • 10

Your next step

Use the same idea in a fresh example. Bring the method and your questions to a discussion with TRICEF, rather than relying on a score alone.

Original TRICEF Academy practice material. Not an official board paper. Open the answer section before printing if you want the answer key included.