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Fermi Talk · estimate · check

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Talk it through

If every pupil in the UK held hands in a line, would it stretch to France? To the Moon?

Talk first. Then decide — and estimate to check the story.

To France UK France France is just across the Channel To the Moon UK zoomed in Earth Moon about 30 Earths apart

Every Fermi question

74 free estimation questions for UK classrooms, from KS3 to GCSE. Put one card on the screen, let the class talk, then reveal a sensible range. No sign-up. A new question is added every day at 10:00 UK time. More free practice is on the students hub, including today’s Keystones.

  1. How tall is the Eiffel Tower?

    Sensible estimate: About 300 to 350 metres

  2. How many footballs would fill the school hall?

    Sensible estimate: Around 100,000 to 300,000 footballs

  3. How many hours of sleep will you get this year?

    Sensible estimate: About 2,500 to 3,500 hours

  4. How many people could stand in the playground?

    Sensible estimate: About 1,000 to 3,000 people

  5. How many times does your heart beat in a school day?

    Sensible estimate: About 20,000 to 40,000 beats

  6. How many litres of water does this class drink in a week?

    Sensible estimate: About 100 to 250 litres

  7. How many pizza slices would cover the classroom floor?

    Sensible estimate: About 2,000 to 6,000 slices

  8. How many double-decker buses stacked would reach the top of Snowdon?

    Sensible estimate: About 200 to 300 buses

  9. How many seconds have you been alive if you are 14?

    Sensible estimate: About 400 million to 500 million seconds

  10. How many phones stacked would reach the height of a double-decker bus?

    Sensible estimate: About 25 to 40 phones

  11. How many packets of crisps does a year group eat in a week?

    Sensible estimate: About 200 to 1,000 packets

  12. How many times will you blink today?

    Sensible estimate: About 10,000 to 20,000 blinks

  13. How many steps would it take to walk once around the school field?

    Sensible estimate: About 300 to 800 steps

  14. How many books are on the shelves in the school library?

    Sensible estimate: About 3,000 to 15,000 books

  15. How many grains of rice are on a dinner plate?

    Sensible estimate: About 3,000 to 10,000 grains

  16. How long would it take to walk from Land’s End to John o’ Groats?

    Sensible estimate: About 5 to 10 weeks

  17. How many sweets would fill a mug?

    Sensible estimate: About 40 to 100 sweets

  18. How many times does a clock tick in a 60-minute lesson?

    Sensible estimate: About 60 (minute hand) or 3,600 (once a second)

  19. How many football pitches would cover the whole school site?

    Sensible estimate: About 5 to 20 pitches

  20. How many bikes could fit in the school car park?

    Sensible estimate: About 200 to 800 bikes

  21. How many sandwiches stacked would reach the top of the classroom door?

    Sensible estimate: About 80 to 150 sandwiches

  22. How many raindrops would fill a bucket?

    Sensible estimate: About 100,000 to 500,000 raindrops

  23. How many songs could you listen to in a weekend?

    Sensible estimate: About 50 to 200 songs

  24. How many tennis balls would fill a wheelie bin?

    Sensible estimate: About 800 to 1,500 tennis balls

  25. How many times will you write your name this school year?

    Sensible estimate: About 800 to 2,500 times

  26. How many paperclips, end to end, would reach across the classroom?

    Sensible estimate: About 150 to 300 paperclips

  27. How many minutes of maths lessons will you have this school year?

    Sensible estimate: About 6,000 to 12,000 minutes

  28. How many people could sit in the school hall for assembly?

    Sensible estimate: About 250 to 700 people

  29. If you had £1 million in £1 coins, would the pile fit in this classroom?

    Sensible estimate: A stack: no. A heap: yes.

  30. If every pupil in the UK held hands in a line, would it stretch to France? To the Moon?

    Sensible estimate: France: yes. Moon: no.

  31. How many pencils, end to end, would reach the classroom ceiling?

    Sensible estimate: About 12 to 25 pencils

  32. How many tea bags does the staffroom use in a day?

    Sensible estimate: About 40 to 150 tea bags

  33. How many sheets of A4 paper would cover the classroom ceiling?

    Sensible estimate: About 600 to 1,500 sheets

  34. How many days would it take to walk from Manchester to London?

    Sensible estimate: About 8 to 16 days

  35. How many times do you chew in one meal?

    Sensible estimate: About 150 to 800 chews

  36. How many footballs would weigh the same as you?

    Sensible estimate: About 100 to 200 footballs

  37. How many stairs are there from the ground floor to the top of the school?

    Sensible estimate: About 30 to 100 stairs

  38. How many windows are there in the whole school?

    Sensible estimate: About 80 to 400 windows

  39. How many minutes are you in school in one week?

    Sensible estimate: About 1,200 to 2,400 minutes

  40. How many apples would weigh the same as you?

    Sensible estimate: About 250 to 600 apples

  41. How many litres does a dripping tap waste in a day?

    Sensible estimate: About 2 to 10 litres

  42. How many exercise books stacked would reach your height?

    Sensible estimate: About 120 to 220 books

  43. How many people live in the UK?

    Sensible estimate: About 60 to 75 million

  44. How many slices of bread does a family eat in a week?

    Sensible estimate: About 50 to 200 slices

  45. How long would it take to count to one million, one number a second?

    Sensible estimate: About 10 days to 3 weeks

  46. How many desks are there in the whole school?

    Sensible estimate: About 400 to 1,200 desks

  47. How many litres of air do you breathe in a one-hour lesson?

    Sensible estimate: About 300 to 700 litres

  48. How many 1p coins stacked would reach the top of your desk?

    Sensible estimate: About 350 to 700 coins

  49. How many school buses would it take to move the whole school?

    Sensible estimate: About 8 to 30 buses

  50. How many times does a school bell ring in a school year?

    Sensible estimate: Around 800 to 1500 times

  51. How many times does a tap drip in one day?

    Sensible estimate: Around 80,000 to 90,000 drips

  52. How many taps are there in the whole school?

    Sensible estimate: 20 to 60 taps

  53. How many times does a school toilet flush in a day?

    Sensible estimate: Between 1000 and 3000 flushes per day

  54. How many steps do you take walking to school?

    Sensible estimate: About 500 to 3,000 steps

  55. How many times does your heart beat in a whole day?

    Sensible estimate: About 100,000 to 150,000 times

  56. How many litres of milk does the school kitchen use in a week?

    Sensible estimate: About 50 to 300 litres

  57. How many bricks are in one outside wall of the school?

    Sensible estimate: About 2,000 to 8,000 bricks

  58. How many words will you read in English this week?

    Sensible estimate: About 3,000 to 15,000 words

  59. How many litres of air do you breathe in a school day?

    Sensible estimate: About 3,000 to 6,000 litres in a school day.

  60. How many times does your heart beat in a year?

    Sensible estimate: About 30 to 50 million times

  61. How many footballs would fit along the white line of a pitch?

    Sensible estimate: About 400 to 550 footballs

  62. How many pieces of toast would cover the dinner table?

    Sensible estimate: About 80 to 250 slices

  63. How many litres of water does a school toilet flush use in a day?

    Sensible estimate: About 2,000 to 10,000 litres per day.

  64. How many pupils in this school could hold hands around the building?

    Sensible estimate: About 80 to 250 pupils

  65. How many breaths do you take in a maths lesson?

    Sensible estimate: About 600 to 1,200 breaths

  66. How many times does a tap drip in a school day?

    Sensible estimate: Between 1,000 and 10,000 drips

  67. How many times does your heart beat in a 60-minute lesson?

    Sensible estimate: Between 3,000 and 6,000 beats, depending on how active or relaxed you are.

  68. How many times will a school bell ring in a school year?

    Sensible estimate: Between 1,000 and 2,000 times

  69. How many times does a school bell ring in one school year?

    Sensible estimate: Between 1,000 and 2,000 times.

  70. How many times will you breathe during one school day?

    Sensible estimate: About 5,000 to 10,000 breaths in a school day.

  71. How many times will you wash your hands this school year?

    Sensible estimate: About 1,000 to 1,500 times in a school year

  72. How many times does your heart beat in a whole year?

    Sensible estimate: About 30 million to 50 million times a year

  73. How many times will you turn on a tap in one week?

    Sensible estimate: About 50 to 100 times a week

  74. How many times will you turn on a tap in one year?

    Sensible estimate: About 2,000 to 6,000 times a year