Mini Minds Hub · Free printable
Pi Day Pizza Lab: Free Printable Worksheet for Year 6
- ForYear 6
- StageKey Stage 2
- CostFree
- FormatPrintable PDF
Pi Day Pizza Lab is a free printable maths worksheet for Year 6 (ages 10 to 11). Children measure round objects with string, look for a pattern in their results, then use a pizza menu rule to work out areas and prices. It needs string, a ruler, a pencil and a calculator. Page 2 gives the grown-up notes, help ideas, a stretch task and the answers.
It comes from the Mini Minds Hub, the free library of printables from Jaques of London, the British games and toy company that has been making games for families since 1795. Print both pages, give page 1 to your child and keep page 2 for yourself. Black and white printing works well.
What is on the sheet
Children start with a table. They measure the distance across several round objects and the length of string that goes round each one, then divide the string length by the diameter and look for a pattern. Next comes a pizza menu with a price rule of £1 for every 75 cm². Children price a small pizza, then find the area and price of a medium pizza given by its radius and a large pizza given by its diameter. There is space to answer each question.
- Round thing
- Diameter (cm)
- String round it (cm)
- String ÷ diameter
- Look at your last column. What number are all three close to?
- Menu rule: £1 for every 75 cm². Price the small pizza.
- A medium pizza has a radius of 15 cm. Find its area and its price.
- A large pizza has a diameter of 40 cm. Find its area and its price.
How to measure round things with string
Choose round objects
Pick things with a clear circular edge, such as a jar lid, a mug, a roll of tape or a plate. Flat objects are easier to wrap than tall ones.
Find the diameter
The diameter is the distance straight across the middle. Lay the ruler across the widest part and read it in centimetres.
Wrap the string
Run the string once around the edge, then mark where it meets itself. Keep it snug but not stretched.
Straighten and measure
Lay the marked string along the ruler and read the length. Then use a calculator to divide the string length by the diameter and write the result in the last column.
Why a pizza lab for pi?
Pi Day is celebrated on 14 March, often with maths activities and with pies and pizzas, because the names sound alike and the shapes are round. Pi is a number that links every circle to its own width. Its digits go on for ever without repeating. Measuring real objects with string lets children discover that link for themselves before anyone tells them about it.
The second half of the sheet puts circles to work. Pizza menus give a good reason to find area, because a bigger pizza costs more. Children must decide whether they are given a radius or a diameter, then use the area of a circle, which is pi × radius × radius. This idea is usually taught in Key Stage 3, so a grown-up may need to introduce it first.
Quick circle facts
- The distance all the way round a circle is called its circumference.
- The radius of a circle is half of its diameter.
- Pi is a number with digits that never end and never repeat.
- Area is measured in square units, such as square centimetres, written cm².
- Pi Day is celebrated every year on 14 March.
Skills and curriculum link
- Measuring with string and a ruler
- Spotting a pattern in data
- Radius and diameter
- Area of a circle
- Multi step money problems
- Using a calculator
Ideas for the grown-up
- Pi comes firstThe table is the way into pi. Let children find the pattern themselves before you name it. Then you can say it is called pi.
- Share the area ruleFor the menu questions, children need area = pi × radius × radius. Check they have met this rule. If not, tell them before they start.
- Radius or diameterAsk, "Which one is this question giving us?" Switching between the two is where most slips happen.
- Calculator useA calculator with a pi button is ideal. Otherwise use the value of pi your class uses. Agree it before starting so everyone gets the same answers.
Key words
- DiameterThe distance straight across a circle, through the middle.
- RadiusThe distance from the middle of a circle to its edge. It is half of the diameter.
- CircumferenceThe distance all the way round the outside of a circle.
- AreaThe amount of flat space inside a shape, measured in square units.
- PiA special number used with circles. Its digits never end.
- Square centimetreA unit for area. It is written cm².
How to use it
- Print both pages. Page 1 is for your child. Keep page 2, which has the notes and answers.
- Give your child string, a ruler and a calculator. Find some round objects around the house or classroom.
- Complete the table together the first time. Before the menu questions, make sure your child has met the rule for the area of a circle, and share it if not.
- Work through the menu questions. Ask, "Is this a radius or a diameter?" and "How did you work that out?"
- Check against page 2. Come back another day and try different round objects. Repeating a familiar activity builds confidence.
Help, stretch and game ideas
If it feels too hard
Use whole centimetres only and let children check the string measurement with a partner. Give a times table grid for the area questions. Write the area rule on a card so children can focus on the steps, and do the first menu question together.
To stretch confident children
Ask whether a large pizza is better value than two small ones. Use the areas and prices to explain. Then invent your own menu rule, such as a different price for each block of area, and test which pizza size gives the best deal.
Make it a game
Run a pizza shop role play. One child is the chef who names a radius, and the other works out the area and price. Swap roles after each order. Use a calculator to check, and give a point for each correct price.
Mistakes to watch for
Watch forA child uses the diameter where the radius is needed, so the area comes out far too big.
Try thisAsk them to halve the diameter first and mark it as the radius on a quick sketch before using the area rule.
Watch forA child multiplies the radius by itself but forgets pi, or multiplies the radius by two instead of by itself.
Try thisWrite the rule out in words: pi, times the radius, times the radius again. Tick each part as it is used.
Watch forThe string is pulled tight or left loose, so the table results are far from the others.
Try thisMeasure again with a partner holding the start point. Wrap the string snugly once, then compare the results.
Talk about it
- Why do you think the string had to go all the way round the edge?
- What did you notice about your last column?
- How can you tell if a question gives you the radius or the diameter?
- Why is area measured in square centimetres and not just centimetres?
- Would you rather buy one large pizza or two small ones? Why?
- What other round things could you measure to test your pattern?
Take it off the page
Round object hunt
Find ten round things at home. Measure across and round each one with string, then compare results with a friend or sibling.
Paper pizza menu
Cut circles from paper in different sizes. Write the radius on each, make up a price rule and create a menu with a price for each pizza.
Plate drawing
Draw round a plate and a bowl. Use a ruler to find each diameter, then mark the radius and say how the two are linked.
Who it is for
Parents
Sit beside your child for the table, then let them lead. Before the menu questions, share the area of a circle rule if they have not met it. Praise careful measuring and clear thinking.
Teachers
Use it as a practical lesson on circles, a homework task or a table activity. Circle area is usually taught in Key Stage 3, so teach the rule first or use the sheet as an extension for confident mathematicians.
Home educators
Gather string, a ruler and a calculator, then let your child hunt for round objects around the house. Pair it with cooking talk or a trip to a pizza place. Repeat with new objects for revision.
Where this fits
Before this sheet, children learn to measure accurately, name the parts of a circle, including the radius and diameter, and find the area of simpler shapes such as rectangles and triangles. They also get used to working with money and multi step problems.
After this, children meet circumference and area of circles in more formal ways, usually in Key Stage 3. The pattern they find in the string table is the idea behind those later rules, so this sheet gives them a head start.
Questions parents and teachers ask
- What age is Pi Day Pizza Lab for?
It is written for Year 6 (ages 10 to 11), in Key Stage 2. Confident Year 5 children may manage the table. The menu questions ask for the area of circles, so some may need support from a grown-up.
- Do children need to know about pi first?
They will need pi, or the area rule, for the menu questions. These ask for the area of circular pizzas, which uses pi × radius × radius. This is usually taught in Key Stage 3, so a grown-up may need to introduce it. The string table is a good way in.
- What do we need to do the sheet?
You need string, a ruler, a pencil and a calculator. Gather a few round objects too, such as jar lids, mugs or plates. A calculator with a pi button is helpful for the area questions.
- What if it feels too hard?
Use whole centimetres only and let children check the string measurement with a partner. Give a times table grid for the area questions. Do the first menu question together and write out the area rule step by step.
- Is it free and screen free?
Yes. It is free to print for home and classroom use. It is a screen free activity that needs only paper, string, a ruler and a pencil. A calculator is fine for the table.
- Can teachers use it in class?
Yes. Teachers can use it as a practical task, a homework activity or a table activity. It needs no preparation beyond printing and finding string. Remember to teach the area of a circle rule first if the class has not met it.
- 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, and works well with real round objects.
Preview the full PDF
Made by Jaques of London, making games for families since 1795. A printable supports classroom learning and does not replace a teacher.