A variable is a labelled box that stores a value, like a score or a number of lives. Programs can set a variable and change it as the program runs. Year 2 coders trace short programs to find a variable’s final value.
What your child will learn
- Know that a variable stores a value with a name
- Follow “set” and “change” blocks step by step
- Work out the final value of a variable
Keeping score
Every game with a score uses a variable. “Set score to 0” starts it; “change score by 1” adds one each time you collect a star. Working through a program one line at a time — tracing it — is how programmers check what a variable will be.
Example questions
Here are a few questions like the ones in the first quest. Can you solve them?
1. What is coins at the end?
Show answer
Answer: 1. coins starts at 4. 4 − 3 = 1. So coins ends at 1.
2. What is coins at the end?
- 1
- 2
- 3
- 0
Show answer
Answer: 0. coins starts at 3. 3 − 3 = 0. So coins ends at 0.
3. What is coins at the end?
Show answer
Answer: 5. coins starts at 0. 0 + 5 = 5. So coins ends at 5.
Tips for grown-ups
- Keep score in a board game on paper and talk about “changing score by 2”.
- Use a box labelled “sweets” and add or take away while counting.