Trace the program
A trace table with the value of every variable after each step, and the output.
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Teaching Guide: Flowcharts and Algorithms
Computational thinking can be learnt away from the computer: following an algorithm step by step, predicting what it will print, finding its bug and putting its instructions in order. These are the tasks of PISA 2025’s Learning in the Digital World and of the computing curriculum. This free generator makes flowchart and pseudocode worksheets with programs the generator runs, so every answer and trace table in the answer key is right.
- For
- Elementary 5th, 6th · Middle & High 7th, 8th, 9th, 10th (ages 10-15)
- Subject
- Technology › Computational Thinking
- Includes
- Student sheet and answer key
- Format
- A4, to print or save as PDF; new exercises every time
- Price
- Free, no sign-up
- Available in
- Catalan, Spanish, English
Student worksheet 
Answer key Complete
Three options for the missing step: only one gives the output.
Debug
The program prints the wrong thing: find the wrong step and fix it.
Order
Jumbled instructions that only give the output in one order.
Draw
From pseudocode to a flowchart, with the right flowchart in the answer key.
Flowchart or pseudocode
Every exercise prints as a flowchart or as pseudocode with English keywords.
Frequently asked questions about the flowchart worksheets
Which grades are they for?
Level 1 (sequence and selection) is for Grades 5-6, level 2 (loops) for Grades 7-8 and level 3 (loops with decisions, div and mod) for Grades 9-10.
What is a trace table?
A table with one row for every step that gives a variable a value or prints something. Filling it in is the surest way to know what a program does without a computer.
What do div and mod mean?
They are integer division: 17 div 5 = 3 is the quotient and 17 mod 5 = 2 the remainder. They tell whether a number is even (n mod 2 = 0) or split a number into its digits (n mod 10 and n div 10).
How do I know the answers are right?
The programs are not written by hand: the generator builds them as trees and runs them with an interpreter. In the bug exercises it checks that only one correction works, and in the ordering ones that only one order gives the output.
Which other worksheets go well with these?
Unplugged coding with the robot on a grid to start with, logical reasoning for sequences and patterns and algebraic expressions for variables. You will find every resource in technology worksheets.
How do I print only the answer key?
Click Print and choose “Answer key”, or “Worksheet and answer key” for both. You can also save it as a PDF from your browser’s print dialog.
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