1. Replace twos with threes

  2. Divisibility test

  3. Reciprocal of a number (1/x)

  4. The Snail in the Well

  5. 1, 2, Fizz, 4, Buzz

  6. Complex Binary Numbers

  7. Find the smallest number bigger than the input whose digital sum is the input
  8. Be as evil as possible
  9. Is this even or odd?
  10. Add two numbers
  11. 8 8's make 1000

  12. Calculate the sum of ILD

  13. Given a number, print out its "collective sum"
  14. Quartic Summation
  15. Find the n-th perfect power!
  16. Dutch Burgerservicenummer (BSN) eleven-test
  17. Count without 3
  18. The Non-Zero Digital Product Challenge
  19. Opposite of the digital root!

  20. Show me the nearest demon

  21. Find number of ones to get a number using + and *

  22. Fibonacci-orial

  23. Find the Factorial

  24. Given an int input n, print out n*reversed(n)

  25. Range, Reverse, Sum!
  26. Basic Calculator

  27. How many squares, cubes, fourth powers, etc. do I need to sum to n?

  28. Generate a number by using a given list of numbers and arithmetic operators
  29. Sum the odd square numbers less than N
  30. Inverse function

  31. Let's decrease the monotony

  32. Sum the numbers on standard in

  33. Pascal's Alternating Triangle

  34. Can even numbers become prime?

  35. Simple State Sales Tax Calculator

  36. What is the missing number (divisibility by 9)

  37. Create an omnifix calculator
  38. Square pyramidal numbers

  39. Olympic Rings Sequence

  40. Diluted Integer Sums
  41. The Luhn algorithm for verifying credit card numbers, etc

  42. Addition/Multiplication table generator
  43. Am I a golfy array?

  44. Circularly moving sum
  45. 24 and 12 Hour Times

  46. Reduce a number by its largest digit
  47. Back to the Basics of Math
  48. Is my barcode valid?

  49. What do you get when you multiply 6 by 9? (42)

  50. Accumulate some L.s.d

  51. Match the Striking Clock
  52. Sort the unique numbers in a multiplication table
  53. Print the digital root
  54. Create an N-Dimensional Simplex (Tetrahedron)

  55. Linear interpolation of the Fibonacci sequence

  56. The forbidden built-in
  57. The working time calculator

  58. Encrypted In Numbers!

  59. 2 factors factorization

  60. Repeated reciprocal

  61. Easy-to-multiply numbers
  62. A+B using C++ language

  63. Greatest Common Divisor

  64. Leyland Numbers

  65. Can this number be written in (3^x) - 1 format?
  66. Abandon all squares, ye who divide me
  67. Find All Distinct Gozinta Chains
  68. List all ordered partitions of n
  69. Count Up, Replace, Repeat!

  70. Distance between two points in n-dimensional space

  71. Calculating (3 + sqrt(5))^n exactly

  72. Calculate Standard Deviation

  73. If A-B be in A-B A else B eh?
  74. X+Y=Z - but in which base?

  75. Be as fair as possible

  76. 52 Week Challenge

  77. Shortest Addition Chain

  78. Find i^n, given n

  79. Raise integer x to power x, without exponentiation built-ins
  80. Notcalc (Calculate the wrong answer)

  81. A regex to match three consecutive integers iff the third integer is the sum of the first two
  82. Increment an Array
  83. Calculate the Upper Divmod
  84. Multiply a string by a number!

  85. Advent Challenge 3: Time to remanufacture the presents!
  86. Mod-balanced lists
  87. Electrical outlet

  88. Simplify a square root

  89. Compute the result of an equation, but with selectable operator precedence

  90. An Array of Challenges #3: Moving Averages

  91. How much present did you get for Christmas?
  92. Length of a Sumac sequence

  93. Additive Persistence
  94. Divide one number by another
  95. Division and remainder

  96. Output the largest number with the fewest digits
  97. Find the next 1-sparse binary number
  98. Traveling on a flat Earth

  99. Simple integer operation calculator
  100. Summation from a to b