“Move over there.”
The robot doesn’t move.
“Go to the square beside the chair.”
Still nothing.
The child giving instructions pauses. Their partner, playing the robot, is waiting for a command they can follow.
“How about this: move forward one square, then turn right?”
Now the robot moves—and the learning begins.
This simple activity introduces an important part of STEM—science, technology, engineering, and mathematics: giving clear instructions, testing them, and making corrections. Children can explore the logic behind programming using a paper grid, a small toy, and their own ideas.
No computer is needed.
The challenge is to guide a “robot” from a starting square to a destination using a sequence of commands. One child becomes the programmer. Another follows the instructions exactly, moving a token across the grid.
Begin by drawing a grid of five rows and five columns on a sheet of paper. Mark a starting square and a destination, then place a small toy or paper arrow at the start. The arrow is particularly useful because it shows which direction the robot is facing.
Agree on three commands:
- Move forward one square.
- Turn left without leaving the square.
- Turn right without leaving the square.
The turning rule matters. Turning changes the robot’s direction; moving forward changes its position. Keeping those actions separate makes the instructions easier to interpret and test.
Invite the programmer to write or arrange a complete set of commands before the robot begins. For children who aren’t yet comfortable writing, draw simple command cards they can place in order. Older children can number their instructions and predict where the robot will finish.
Then run the program.
The robot follows each command in sequence, even when the programmer notices that something is going wrong. If an instruction would take it beyond the grid, stop and mark that point. Resist the temptation to quietly fix the route while it’s running: seeing what the instructions actually produce is part of the investigation.
Perhaps the robot turns too early. Perhaps it reaches the correct row but faces the wrong direction. These outcomes create a useful question: Which instruction needs to change?
In programming, finding and correcting errors is called debugging. Children can practise it by tracing their commands one at a time, identifying where the result first differs from their plan, and revising that part of the sequence.
Encourage specific explanations. “It didn’t work” is a starting point. “We turned right before moving far enough” gives the team something they can act on.
Once children can navigate a simple route, add an obstacle. Shade a square that the robot cannot enter. Now the programmer must plan around a constraint rather than choosing any path across the grid.
You can also invite children to compare two successful routes. Which uses fewer forward moves? Which uses fewer commands overall? Those questions may produce different answers because turns count as commands too.
This is a useful introduction to evaluating a solution. Reaching the destination is one goal; finding a shorter or simpler set of instructions is another. Ask children to decide what they are trying to improve before redesigning their route.
A further variation introduces repetition. Suppose the robot needs to move forward three squares. Instead of writing the same instruction three times, children can create a card that says, “Repeat ‘move forward’ three times.”
This is the idea behind a loop: repeating an instruction or group of instructions a specified number of times. Run both versions and compare them. Do they take the robot to the same place? Which is easier to read? Can another child understand the repeated instruction without extra explanation?
The activity also gives children a reason to consider someone else’s perspective. “Turn left” means the robot’s left, which may be different from the programmer’s. Before starting, let children rotate the paper arrow and practise identifying its left and right sides.
If directional language is a barrier, begin with commands such as “move one square toward the window” and “move one square toward the door.” Once that version is comfortable, introduce orientation and turning as a new challenge.
Make sure children exchange roles. Following instructions can reveal ambiguities that are easy to miss when writing them. The child who confidently creates a route may discover that another person interprets one of the commands differently.
That moment deserves a conversation rather than a correction delivered in frustration. Ask, “What could we change so this instruction has only one meaning?”
At the end, invite children to explain their program to someone who hasn’t watched them build it. Can that person follow the sequence successfully? What information do they need about the starting position and direction?
These questions connect a playful challenge with a practical habit: communicating an idea clearly enough for someone else to use it.
H3S Academy offers hands-on STEM experiences, science workshops, mathematics enrichment, and community learning activities. Explore our Workshops & Events page or contact contact@h3sacademy.com to ask about learning opportunities.
For today, a grid and a paper arrow are enough. Choose a destination, write your instructions, and let the robot show you what happens.
