Bubble Sort Cards: Free Printable Game for Year 7

Bubble Sort Cards is a free printable game for Year 7 (ages 11 to 12), in Key Stage 3. Sort numbers with human swaps. It comes from the Mini Minds Hub, a growing library of free printables from Jaques of London, the British games and toy company that has been making games for families since 1795.

It is two A4 pages. Page 1 is the activity for children. Page 2 is for the grown-up: it has notes on how to use the sheet, help for children who find it hard, a stretch idea, and the answers. Print it at home or in the classroom. Black and white printing works well.

What is on the sheet

This game includes cards to cut out and use and lines for writing.

A look at what children will meet:

• 7
• 3
• 9
• 1
• 5
• 8
• 2
• 6

Who this is for

Year 7 (ages 11 to 12) in Key Stage 3.

Key Stage 3 covers Years 7 to 9, ages 11 to 14. Learners are moving from remembering facts to applying them, so tasks that ask for a reason or a method are worth more than quick answers. Use it at home, in class, on a rainy afternoon or at a family gathering.

What children practise

• Algorithms
• Sorting
• Logical thinking

Pupils act out a bubble sort and see how an algorithm puts numbers in order.

Learning focus and curriculum link

Subject: Computing. Key stage: Key Stage 3. It supports the subject at this level through short, focused practice.

This sheet is a practice and play activity. It supports classroom learning and is not a replacement for it.

How to use it

1. Print both pages. Page 1 is for the child. Keep page 2 for the grown-up.
2. Two players or one. Time to play is about 15 minutes. One player moves cards while the other checks each swap.
3. Work through the activity together the first time. Talk about each choice.
4. Check against the notes on page 2 and the answers.
5. Come back to it another day. Repeating a familiar activity builds confidence.

If it feels too hard

Use only the first five cards and go slowly.

To stretch confident children

Try a reversed row such as 9, 8, 7, 6, 5 and count the swaps.

Make it a game

Play as a team where each person holds one card and swaps places with a neighbour.

Tips for parents and teachers

• Read the rules out loud together before you start, so everyone plays the same game.
• Take turns being the person who reads or checks. It builds listening as well as knowledge.
• Keep rounds short. Two quick games beat one long one.

A screen-free computing activity for Year 7

Children spend a lot of time on screens. This is a screen-free computing activity that needs only paper and a pencil. It works as quiet time after school, a rainy day activity, a holiday boredom buster or a calm moment before bed. Screen-free learning gives eyes a rest and gets children talking, thinking and writing by hand.

Free computing resources for teachers

Teachers can use this game as a starter, a plenary, an early finisher task, a supply teacher resource, a homework task or a table activity. It needs no preparation beyond printing. The learning focus and skills are listed above so you can match it to your planning, and page 2 gives support and stretch ideas for mixed ability groups.

Computing ideas for parents at home

You do not need to be a teacher to use this. Read the sheet through, sit with your child for the first go and let them lead. Short bursts of ten to fifteen minutes work better than long sessions. If you are looking for free computing worksheets for Year 7, or simple home learning for the weekend or school holidays, this is a good place to start.

Home education and tutoring

Home educators and tutors can print this as part of a wider computing plan. It pairs well with books, outdoor play and everyday talk. Because the sheet is free and printable, you can use it again for brothers and sisters or for revision a few weeks later.

Why it helps children learn

Hands-on, paper based activities slow learning down in a good way. Children read carefully, think before they answer and see their own progress on the page. Games and challenges add a reason to keep going. That mix of play and practice is why printable activities like this are popular with parents, teachers and home educators.

Curriculum links for teachers

This sheet supports the areas below. It is matched to the published England frameworks. Please check it against your own school plan.

What children will be able to do

• I can act out a bubble sort.
• I can compare two numbers and swap them if needed.
• I can say how the algorithm puts numbers in order.

Check it worked

Ask these when the sheet is finished. Listen for the reasoning, not just the answer.

1. What do you do when two numbers are in the wrong order?
2. How do you know the list is finished?
3. Could you sort the list a different way?

More like this

• Binary Search Game
• Boolean Truth Tables
• Computing Careers Cards
• Cyberbullying Response Cards

Same subject, one year up: Boolean Truth Tables | Same subject, one year down: Computing Careers Cards

Why sorting matters in computing

Computers sort things all the time. Names go into alphabetical order. Prices go from low to high. Messages go from newest to oldest. A sorting method is a good first example of an algorithm, because the job is easy to understand and the answer is easy to check. Bubble Sort Cards lets children act out one of the simplest sorting methods with eight number cards: 7, 3, 9, 1, 5, 8, 2 and 6.

The national curriculum for England names sorting directly. Its Key Stage 3 computing programme of study says pupils should understand several key algorithms that reflect computational thinking, with sorting and searching given as examples. Wikipedia's article on bubble sort says that, because of its simplicity, the method is often used to introduce the concept of an algorithm to introductory computer science students. It also says that bubble sort is rarely used in practice, because insertion sort generally runs faster and is no more complex. We think both points are worth telling a Year 7 child. It is a good teaching example. It is not what a programmer would pick for a big job.

What the research says children find hard

The Ofsted research review for computing is the main source we use here. It is a review of published research, and it is careful about what is known. We have kept to what it says.

• Pupils often lack a model of what the computer is doing. The review cites Sorva, who says that pupils' misconceptions about programming commonly lack a viable model of program execution and that pupils fail to understand the notional machine they are learning to control. The review says that without a secure mental model, pupils are more likely to make incorrect inferences and develop misconceptions. Acting out each swap with cards gives a child a model they can see and touch.
• Unplugged activities can be ambiguous. The review says that unplugged activities, which expose children to the ideas of computer science without using computers, can be useful in introducing computing concepts to pupils at the early stages of their computing education. It also warns that not all of them are strongly linked to computing subject content, that they might introduce misconceptions, and that activities to teach algorithms can be ambiguous, in opposition to the unambiguous nature of algorithms as precisely defined procedures.
• Prior knowledge changes the value. The review says these activities appear to be more useful when introducing new knowledge. It also warns that they may reduce pupils' desire to study computing when they are not well linked to computing concepts.

What this means for Bubble Sort Cards: keep the rules exact. A child may only compare two cards that sit next to each other. They must swap only if the left card is bigger than the right card. They must move along the row from left to right. The University of Washington lecture notes we read say that, in bubble sort, comparisons are only performed between adjacent elements, and that the elements are swapped if they are in the wrong order. If a child "just fixes" the row by eye, the activity is not showing an algorithm.

What Year 7 children are expected to learn

The national curriculum for England, in its computing programme of study for Key Stage 3, says pupils should be taught to:

• design, use and evaluate computational abstractions that model the state and behaviour of real-world problems and physical systems
• understand several key algorithms that reflect computational thinking [for example, ones for sorting and searching]
• use logical reasoning to compare the utility of alternative algorithms for the same problem
• use 2 or more programming languages, at least one of which is textual, to solve a variety of computational problems; make appropriate use of data structures [for example, lists, tables or arrays]

The aims of the curriculum also say pupils should understand and apply the fundamental principles and concepts of computer science, including abstraction, logic, algorithms and data representation. Bubble Sort Cards works on the second and third points. Children act out a sorting algorithm and, once they have done the sheet, they can ask whether another method would do the job with fewer steps.

Why a card activity can help

A set of cards makes each step visible. The row of eight numbers is the data. The pass along the row is the algorithm. Each swap is a single step that a partner can check. That matches the idea in the Ofsted review that algorithms are first introduced as a sequence of steps and then unpacked through simpler, more concrete examples.

It is fair to say what we do not know. The Ofsted review does not mention sorting algorithms in particular, and it does not report a trial of bubble sort with cards. Its comments on unplugged work are mixed, as shown above. So we see this sheet as a way to build a first picture of a sorting method, to be followed by a teacher's explanation and, ideally, by writing the method as code. We are not claiming it improves test scores.

How to get the most out of Bubble Sort Cards

1. Cut out the cards and lay them in a row. Use the order on the sheet: 7, 3, 9, 1, 5, 8, 2, 6.
2. Say the rule aloud. "Compare two neighbours. If the left one is bigger, swap them. Then move one place to the right."
3. Do one whole pass slowly. Let one player move the cards while the other checks each swap, as the sheet suggests. After pass 1, find where the 9 is. It should be at the end.
4. Start the next pass. The last card is now in the right place, so there is no need to look at it again. The next pass can stop one card earlier.
5. Stop when a whole pass has no swaps. That is how you know the row is in order.
6. Count. Count the swaps and the passes. Write both numbers down. Compare with a partner and with page 2.
7. Try the stretch. Use the reversed row 9, 8, 7, 6, 5 and count the swaps. We work out the answer in the questions below.

Common mistakes, and what to say

• Comparing cards that are not next to each other. Say: "Only neighbours. The algorithm cannot see the whole row at once."
• Swapping when the cards are already in order. Say: "Swap only when the left card is bigger."
• Stopping after one pass. One pass puts only the largest card in place. Ask: "Is the whole row sorted? How do you know?"
• Looking at the whole row and moving cards to the right spot. That can sort the cards, but it is not bubble sort. Say: "A computer cannot glance at the whole row. What would it do?"
• Thinking the method is fast because it works. It does work. It is also slow for long lists. See questions 11 to 14.

Why teachers matter to us

We are a games company, and we have been making games for families since 1795. A printable is a useful extra. It is not a teacher, and we would not want it to be. A teacher can see the moment a child's picture of an algorithm goes wrong, and can fix it before it sets. That matters in computing, where the Ofsted review says misconceptions can form when pupils lack a secure model of what happens.

The research on teacher quality is not about computing, so we use it carefully. A 2011 interim report for the Sutton Trust looked at the UK and drew on examples from maths and reading. It found that in one year with a very effective maths teacher, pupils gain 40% more in their learning than with a poorly performing maths teacher. That figure is about maths, not computing. The report also found that for poor pupils the difference between a good and a bad teacher is a whole year's learning, and that things like experience, degrees and certification explain less than 8% of teacher quality. A University of Bristol study found considerable variability in teacher effectiveness. We take from this that the people in the room matter most, and we want to make their work a little easier.

A caution on the Sutton Trust figures: the report draws on US studies as well as English ones. The 40% compares a very effective teacher (at the 84th percentile) with a poorly performing one (at the 16th percentile). The figure that paper credentials explain less than 8% of teacher quality comes from US research. We use them as pointers, not as a promise about any one child.

Why education matters to us

The national curriculum says that a high-quality computing education equips pupils to use computational thinking and creativity to understand and change the world. A child who sees how a computer puts a list in order has taken a step towards understanding the tools they use every day. Jaques of London has made games for families since 1795, and a good game is often the easiest way into a hard idea. The Mini Minds Hub is free and screen-free, so that learning can start at the kitchen table or in a corner of the classroom.

Bubble Sort Cards: 20 questions and answers

1. What is an algorithm?

The Ofsted review describes algorithms as precisely defined procedures, and says they are introduced as a sequence of steps. Bubble sort is a set of steps that always puts a row of numbers in order.

2. Why is it called bubble sort?

Wikipedia says the name comes from the way the larger elements "bubble" up to the top of the list. On the sheet, the biggest number drifts to the right end.

3. What is a pass?

A pass is one trip along the row, comparing each pair of neighbours and swapping if they are out of order.

4. What happens in pass 1 with 7, 3, 9, 1, 5, 8, 2, 6?

Compare 7 and 3: swap. 7 and 9: no swap. 9 and 1: swap. 9 and 5: swap. 9 and 8: swap. 9 and 2: swap. 9 and 6: swap. The row is now 3, 7, 1, 5, 8, 2, 6, 9. That is 7 comparisons and 6 swaps. We worked this out by hand and with a short script.

5. What does the row look like after each pass?

After pass 2: 3, 1, 5, 7, 2, 6, 8, 9. After pass 3: 1, 3, 5, 2, 6, 7, 8, 9. After pass 4: 1, 3, 2, 5, 6, 7, 8, 9. After pass 5: 1, 2, 3, 5, 6, 7, 8, 9. Pass 6 makes no swaps, so we stop.

6. Why does the biggest number always end up at the end after pass 1?

The University of Maryland notes explain that the largest element is swapped repeatedly until it reaches the end, so after one pass the last entry is in the right place. After two passes the last two are right, and so on.

7. How many passes can it take at most?

The Maryland notes say a list of n items needs n - 1 passes in total, because once the last n - 1 entries are in order, all are. With 8 cards that is at most 7 passes.

8. Why do we shorten each pass?

The cards at the right end are already in place. The Washington notes say each pass considers each pair of adjacent elements that are unsorted, so later passes check fewer pairs.

9. How do we know when to stop?

When a whole pass makes no swaps. The Washington notes show code that uses a flag set to true at the start of each pass and set to false whenever a swap happens. The loop ends once a pass makes no swaps. A list that is already sorted finishes after one pass.

10. How many swaps did our row need in total?

15 swaps and 27 comparisons if each pass is shortened. The 15 matches the number of pairs of cards that start in the wrong order, which we also counted separately. We worked this out ourselves, so check your own count against page 2.

11. What is the worst case?

The Washington notes say the worst case is when the data is in completely the wrong order. The Maryland notes use 5, 4, 3, 2, 1 as a reversed list and show that every comparison causes a swap.

12. How many swaps does the stretch row 9, 8, 7, 6, 5 need?

10. The Maryland example with five reversed items does 4, then 3, then 2, then 1 swaps, which adds to 10. For 8 reversed cards the same pattern gives 28 swaps. That figure is our own arithmetic.

13. What is the best case?

A list that is already in order. The Washington notes say it takes one pass, which is O(n) time. The Maryland notes agree, once the early-stop check is added.

14. What does O(n squared) mean?

It is a way of describing how the work grows as the list grows. Both sets of notes give bubble sort a worst-case and average time of O(n squared). In plain words, a longer list takes far more steps. If you double the list, you roughly quadruple the work. That is our plain-English reading of the notation.

15. Does bubble sort make more swaps than other simple methods?

The Washington notes say bubble sort performs many more swaps than selection sort, which is a drawback when elements are large. Both have the same worst-case growth.

16. Why is it rarely used in real programs?

Wikipedia says insertion sort generally runs faster and is no more complex. We have not tested the two methods ourselves.

17. What happens if two cards have the same number?

The Maryland notes say the method is stable. Equal elements are never swapped, so their order is kept. Try it with two 4s of different colours.

18. Is acting out the algorithm the same as writing code?

No. The curriculum asks pupils to use two or more programming languages, at least one textual, and to make appropriate use of data structures such as lists, tables or arrays. The row of cards is like a list. Writing the loop in code is the next step.

19. Can we play it as a team?

Yes. The sheet suggests each person holding one card and swapping places with a neighbour. Make sure only one pair acts at a time, to keep the rule exact.

20. Where can I find more Year 7 computing sheets?

See the More like this section below, or browse all Year 7 printables in the Mini Minds Hub.

Sources

1. Ofsted, Research review series: computing (2022): gov.uk.
2. Department for Education, National curriculum in England: computing programmes of study: gov.uk.
3. University of Washington, CSS 501 Lecture Notes 12, Sorting: courses.washington.edu.
4. Wyss-Gallifent, University of Maryland, CMSC 351 notes on BubbleSort (2024): math.umd.edu.
5. Wikipedia, Bubble sort: wikipedia.org.
6. Sutton Trust, Improving the impact of teachers on pupil achievement in the UK, interim findings (2011): dera.ioe.ac.uk.
7. Slater, Davies and Burgess, University of Bristol CMPO Working Paper 09/212 (2009): bristol.ac.uk.

Frequently asked questions

What age is Bubble Sort Cards for?

It is written for Year 7 (ages 11 to 12), in Key Stage 3.

What will children practise?

Pupils act out a bubble sort and see how an algorithm puts numbers in order.

How do I use it?

Two players or one. Time to play is about 15 minutes. One player moves cards while the other checks each swap.

What if it feels too hard?

Use only the first five cards and go slowly.

Is it free?

Yes. It is free to print for home and classroom use.

Is Bubble Sort Cards suitable for teachers to use in class?

Yes. Teachers can use it as a starter, plenary, early finisher task, homework or table activity. It needs no preparation beyond printing.

Is this a screen-free activity?

Yes. It is a screen-free printable that needs only paper and a pencil, so it works well for quiet time, rainy days and school holidays.

Can I use it for home education?

Yes. Home educators and tutors can use it on its own or as part of a wider plan. It is free to print again for brothers, sisters or revision.

How long does it take?

Most children finish page 1 in 10 to 20 minutes. The notes on page 2 suggest ways to make it shorter or longer.

Do I need to print in colour?

No. It prints well in black and white on plain A4 paper.

More free printables

More for Key Stage 3 | More computing printables | Free printable games | All Mini Minds Hub resources