← Number puzzles and digit counting lesson New set →

Number Puzzles Worksheet for Maths Olympiad

Maths Olympiad topic 25: Number puzzles and digit counting · Set 519 · 40 questions
TalentJR

How to solve it (Count place by place): Count a digit place by place: first in the ones place, then in the tens place (a number like 33 counts twice). Page numbers: pages 1–9 use 1 digit each, 10–99 use 2, 100–999 use 3. A 3 × 3 magic square made of nine numbers: each row adds up to (sum of all nine) ÷ 3.

NameDateTime takenScore ___ / 40
  1. 1.How many times is the digit 6 written when you write all the numbers from 1 to 61? (a) 7 (b) 8 (c) 9 (d) 6
  2. 2.How many times is the digit 5 written when you write all the numbers from 1 to 43? (a) 3 (b) 5 (c) 2 (d) 4
  3. 3.The numbers 9 to 17 are placed in a 3 × 3 magic square, so every row, column and diagonal has the same sum. What is that sum? (a) 13 (b) 42 (c) 117 (d) 39
  4. 4.A book has 102 pages, numbered 1, 2, 3 and so on. How many digits are printed to number all the pages? (a) 204 (b) 189 (c) 199 (d) 198
  5. 5.A book has 198 pages, numbered 1, 2, 3 and so on. How many digits are printed to number all the pages? (a) 486 (b) 477 (c) 396 (d) 487
  6. 6.A book has 143 pages, numbered 1, 2, 3 and so on. How many digits are printed to number all the pages? (a) 322 (b) 312 (c) 286 (d) 321
  7. 7.The numbers 16 to 24 are placed in a 3 × 3 magic square, so every row, column and diagonal has the same sum. What is that sum? (a) 20 (b) 180 (c) 60 (d) 63
  8. 8.How many times is the digit 5 written when you write all the numbers from 1 to 65? (a) 6 (b) 17 (c) 18 (d) 16
  9. 9.How many times is the digit 6 written when you write all the numbers from 1 to 63? (a) 11 (b) 8 (c) 6 (d) 10
  10. 10.A book has 237 pages, numbered 1, 2, 3 and so on. How many digits are printed to number all the pages? (a) 603 (b) 604 (c) 594 (d) 474
  11. 11.A book has 70 pages, numbered 1, 2, 3 and so on. How many digits are printed to number all the pages? (a) 132 (b) 140 (c) 122 (d) 131
  12. 12.How many two-digit numbers have digits that add up to 7? (a) 10 (b) 6 (c) 8 (d) 7
  13. 13.How many times is the digit 7 written when you write all the numbers from 1 to 59? (a) 4 (b) 5 (c) 7 (d) 6
  14. 14.How many two-digit numbers have digits that add up to 4? (a) 3 (b) 4 (c) 5 (d) 10
  15. 15.A book has 215 pages, numbered 1, 2, 3 and so on. How many digits are printed to number all the pages? (a) 528 (b) 538 (c) 430 (d) 537
  16. 16.A book has 227 pages, numbered 1, 2, 3 and so on. How many digits are printed to number all the pages? (a) 454 (b) 573 (c) 574 (d) 564
  17. 17.A book has 30 pages, numbered 1, 2, 3 and so on. How many digits are printed to number all the pages? (a) 51 (b) 42 (c) 52 (d) 60
  18. 18.How many times is the digit 8 written when you write all the numbers from 1 to 85? (a) 8 (b) 12 (c) 15 (d) 14
  19. 19.A book has 59 pages, numbered 1, 2, 3 and so on. How many digits are printed to number all the pages? (a) 118 (b) 110 (c) 100 (d) 109
  20. 20.The numbers 19 to 27 are placed in a 3 × 3 magic square, so every row, column and diagonal has the same sum. What is that sum? (a) 207 (b) 69 (c) 72 (d) 23
  21. 21.How many times is the digit 6 written when you write all the numbers from 1 to 60? (a) 6 (b) 5 (c) 7 (d) 8
  22. 22.A book has 161 pages, numbered 1, 2, 3 and so on. How many digits are printed to number all the pages? (a) 376 (b) 366 (c) 375 (d) 322
  23. 23.A book has 80 pages, numbered 1, 2, 3 and so on. How many digits are printed to number all the pages? (a) 151 (b) 152 (c) 142 (d) 160
  24. 24.How many times is the digit 6 written when you write all the numbers from 1 to 52? (a) 4 (b) 6 (c) 3 (d) 5
  25. 25.A book has 187 pages, numbered 1, 2, 3 and so on. How many digits are printed to number all the pages? (a) 453 (b) 374 (c) 444 (d) 454
  26. 26.How many times is the digit 7 written when you write all the numbers from 1 to 39? (a) 2 (b) 3 (c) 4 (d) 5
  27. 27.How many two-digit numbers have digits that add up to 13? (a) 6 (b) 14 (c) 7 (d) 5
  28. 28.The numbers 4 to 12 are placed in a 3 × 3 magic square, so every row, column and diagonal has the same sum. What is that sum? (a) 8 (b) 27 (c) 72 (d) 24
  29. 29.A book has 181 pages, numbered 1, 2, 3 and so on. How many digits are printed to number all the pages? (a) 362 (b) 426 (c) 436 (d) 435
  30. 30.The numbers 18 to 26 are placed in a 3 × 3 magic square, so every row, column and diagonal has the same sum. What is that sum? (a) 69 (b) 66 (c) 198 (d) 22
  31. 31.The numbers 7 to 15 are placed in a 3 × 3 magic square, so every row, column and diagonal has the same sum. What is that sum? (a) 11 (b) 36 (c) 99 (d) 33
  32. 32.How many times is the digit 3 written when you write all the numbers from 1 to 95? (a) 21 (b) 19 (c) 9 (d) 20
  33. 33.How many times is the digit 8 written when you write all the numbers from 1 to 87? (a) 16 (b) 17 (c) 8 (d) 14
  34. 34.How many times is the digit 3 written when you write all the numbers from 1 to 92? (a) 9 (b) 19 (c) 20 (d) 18
  35. 35.A book has 20 pages, numbered 1, 2, 3 and so on. How many digits are printed to number all the pages? (a) 31 (b) 32 (c) 40 (d) 22
  36. 36.A book has 36 pages, numbered 1, 2, 3 and so on. How many digits are printed to number all the pages? (a) 63 (b) 64 (c) 72 (d) 54
  37. 37.How many two-digit numbers have digits that add up to 3? (a) 4 (b) 3 (c) 10 (d) 2
  38. 38.A book has 170 pages, numbered 1, 2, 3 and so on. How many digits are printed to number all the pages? (a) 340 (b) 393 (c) 403 (d) 402
  39. 39.How many times is the digit 6 written when you write all the numbers from 1 to 57? (a) 4 (b) 6 (c) 5 (d) 7
  40. 40.How many times is the digit 1 written when you write all the numbers from 1 to 68? (a) 18 (b) 17 (c) 16 (d) 6

Answer key

  1. 8
  2. 4
  3. 39
  4. 198
  5. 486
  6. 321
  7. 60
  8. 17
  9. 10
  10. 603
  11. 131
  12. 7
  13. 6
  14. 4
  15. 537
  16. 573
  17. 51
  18. 14
  19. 109
  20. 69
  21. 7
  22. 375
  23. 151
  24. 5
  25. 453
  26. 4
  27. 6
  28. 24
  29. 435
  30. 66
  31. 33
  32. 20
  33. 16
  34. 19
  35. 31
  36. 63
  37. 3
  38. 402
  39. 6
  40. 17

Free maths olympiad lessons, practice and worksheets at talentjr.in/maths-olympiad