Algorithms: put the steps in the right order: what children learn
An algorithm is a list of steps to follow, in the right order, to complete a task or solve a problem. Computers cannot guess what we mean, so a program is an algorithm written in a way a device can follow exactly. In Key Stage 1, children learn what algorithms are and that programs only work when the instructions are precise and in the right order.
In this game, children see the steps for an everyday task, such as brushing their teeth or planting a seed, mixed up. They drag them into the right order. Every set has only one order that works: you cannot cover a seed before it is in the hole, and you cannot rinse your mouth before you have brushed. Talking about why each step must come where it does is the start of computational thinking.
This topic covers a Key Stage 1 statutory requirement in the National Curriculum in England (Subject content): pupils should be taught to “understand what algorithms are, how they are implemented as programs on digital devices, and that programs execute by following precise and unambiguous instructions”. The programme of study sets this for the whole of Key Stage 1, so schools choose when to teach it; we have placed this game in Year 1 (ages 5–6).
There is no direct equivalent in the US Common Core State Standards.
How to play
Put the numbers in order. Use the arrow buttons, or pick one card and then another to swap them. Each game has 5 rounds. After you press Check, the correct order is shown if you got it wrong.
Step by step
- Find the first step. Ask: what do you need to do before anything else can happen? You cannot put toothpaste on a brush until the tube is open.
- Ask “what comes next?”. Build the list one step at a time. Read it aloud as you go: first, next, then, finally.
- Test it. Act the algorithm out exactly as written. If something goes wrong, you have found a bug.
- Fix the bug. Swap or add a step until the algorithm works. Fixing a program is called debugging.
- Try a robot. Floor robots such as Bee-Bots follow arrow presses exactly. Children see that a robot does what you tell it, not what you meant.
Worked examples
Example 1: Planting a seed: what comes first, “Drop the seed in the hole” or “Make a hole in the soil”?
Working: The seed needs somewhere to go, so the hole must be made first.
Answer: Make a hole in the soil.
Example 2: Why does the order of an algorithm matter?
Working: Think about getting dressed. If you put your shoes on before your socks, it goes wrong.
Answer: The task only works if the steps are done in the right order.
Example 3: Programming a floor robot: what do you press after the arrows?
Working: The arrows store the route. The robot only moves when you tell it to start.
Answer: Press GO.
Common mistakes and how to fix them
- Thinking an algorithm has to be on a computer. Recipes, directions and instructions for games are all algorithms. A program is an algorithm a computer can follow.
- Leaving steps out. People can fill the gaps, but computers cannot. Act out the steps exactly to spot what is missing.
- Giving vague instructions such as “go over there”. Practise precise instructions: “take three steps forward, then turn right”.
Activities to try at home
- Ask your child to give you instructions to make a sandwich, and follow them exactly, even when they are silly.
- Write the steps of a morning routine on cards, mix them up and put them back in order.
- Play “robot”: one person gives commands such as “forward 2, turn left” and the other follows them.
- Print the sheet and cut out the steps to order on the table.
Ideas for the classroom
- Use floor robots to program a route on a grid mat.
- Pupils write an algorithm for a simple task; a partner follows it exactly and reports any bugs.
- Sort a mixed-up set of instructions as a group, then test them.
- Play the game on the whiteboard and ask pupils to explain each move.
Free printable game and worksheet
The free printable starts with a game sheet, such as a colour-by-answer picture, an answer maze or a secret-code joke, followed by a worksheet. Both use the same checked questions as the online game, and the answers are on the last page. Print it, or save it as a PDF from your browser’s print menu.
Open the free printable game and worksheet
Frequently asked questions
Why are some steps not in the game, such as turning off the tap?
We only use steps that have one sensible place in the order, so there is exactly one right answer. Turning off the tap could happen at different times, so it is left out.
What is the difference between an algorithm and a program?
An algorithm is the list of steps. A program is those steps written in a form that a computer or robot can follow.
Does my child need a computer for this?
No. Algorithms can be learned without screens, using cards, robots made of people and everyday tasks.