Computer science · Grades K–2

Clear instructions · Revision sheet

Reference sheet for Kindergarten to Grade 2: algorithms, be clear and debugging. Writing steps a friend or robot can follow, and fixing mistakes.

Printable summary of the study guide Clear instructions.

Learn the idea

An algorithm is a list of steps to do a job.

Good instructions are clear, short and in the right order.

A bug is a mistake in the steps. Debugging means finding and fixing it.

Write three steps to tell a friend how to put on a hat.
Your friend followed your steps but ended up in the wrong place. How would you find the bug?

Four practice questions on this topic. Try each one before you open the answer.

A robot is on square 4. → means move 1 forward. ← means move 1 back. Steps: ← → → →. Which square does the robot stop on?
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6 4 → 3 → 4 → 5 → 6
A robot is on square B2 of a grid. Columns A to E go from left to right; rows 1 to 5 go from bottom to top. Each arrow moves it one square: ↑ → ← ←. Which square does it end on?
- A2
- B3
- A3
- A4
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A3 Start at B2, follow ↑ → ← ←, end at A3.
A robot is on square E4 of a grid. Columns A to E go from left to right; rows 1 to 5 go from bottom to top. Each arrow moves it one square: ↓ ← ↑. Which square does it end on?
- E4
- D4
- C4
- D5
Show the answer
D4 Start at E4, follow ↓ ← ↑, end at D4.
A robot is on square D3 of a grid. Columns A to E go from left to right; rows 1 to 5 go from bottom to top. Each arrow moves it one square: ← → ↑. Which square does it end on?
- D5
- E4
- D4
- C4
Show the answer
D4 Start at D3, follow ← → ↑, end at D4.