arithmetic

  1. Easy-to-multiply numbers

  2. Be as fair as possible
  3. Raise integer x to power x, without exponentiation built-ins

  4. Greatest Common Divisor
  5. Notcalc (Calculate the wrong answer)
  6. Dutch Burgerservicenummer (BSN) eleven-test

  7. Is this even or odd?
  8. Range, Reverse, Sum!
  9. A regex to match three consecutive integers iff the third integer is the sum of the first two

  10. The working time calculator

  11. Increment an Array
  12. What do you get when you multiply 6 by 9? (42)

  13. Calculate the Upper Divmod
  14. Count without 3
  15. Add two numbers

  16. Multiply a string by a number!

  17. 1, 2, Fizz, 4, Buzz

  18. Advent Challenge 3: Time to remanufacture the presents!

  19. Mod-balanced lists

  20. 2 factors factorization

  21. Reduce a number by its largest digit

  22. A+B using C++ language

  23. Save American Society!

  24. Electrical outlet

  25. Simplify a square root

  26. Compute the result of an equation, but with selectable operator precedence
  27. Is my barcode valid?
  28. An Array of Challenges #3: Moving Averages

  29. How much present did you get for Christmas?

  30. Find the Factorial

  31. Distance between two points in n-dimensional space
  32. Length of a Sumac sequence

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

  34. Additive Persistence
  35. Divide one number by another

  36. The Luhn algorithm for verifying credit card numbers, etc

  37. Division and remainder
  38. Sum the numbers on standard in

  39. Output the largest number with the fewest digits
  40. Find the next 1-sparse binary number

  41. Traveling on a flat Earth

  42. Simple integer operation calculator
  43. Opposite of the digital root!

  44. Summation from a to b

  45. 8 8's make 1000

  46. 24 and 12 Hour Times

  47. Different Way Forward

  48. Is this number a repdigit?
  49. Square pyramidal numbers

  50. Find the positive divisors!

  51. Am I a golfy array?
  52. Least integer as a product of given factors
  53. Solve the equation `a*x == b` with Int32 arithmetics

  54. Repeated reciprocal
  55. Make two numbers co-prime while preserving their least common multiple

  56. Sharing (characters) is Caring!

  57. Reciprocal of a number (1/x)
  58. Interquartile Mean

  59. Iterated partial sums

  60. Least Common Multiple

  61. Roots and operators

  62. Recursive 2x2 determinant

  63. Wait, but what's e^N?

  64. Fibonacci-orial
  65. Reverse Maths Cycles

  66. Evaluate the primorial of a number
  67. Hack the elections
  68. Back to the Basics of Math
  69. Exponentiation to multiplication to addition
  70. Solve quadratic equation using only 3 variables and arithmetic

  71. Subtract the next numbers

  72. Weapons of Math Instruction

  73. How many peaks in my mountain range?

  74. 2 plus 2 equals fish!
  75. Golf the xᵗʰ root of x
  76. Yes, of course I'm an adult!

  77. The Uncommon Factor Number

  78. Three triangular numbers

  79. Totalling Troublesome T's

  80. Simple State Sales Tax Calculator

  81. Help! My calculator malfunctions!

  82. Find out how Abstractly Capacious™ someone is!

  83. Make your language *mostly* unusable! (Cops' thread)

  84. Divisible by 1000003? Easy, just multiply the last digit by 300001 and add!
  85. When does (x == x+2)?

  86. Blind binary adder
  87. Playing Darts: become an amateur with the most efficient prioritizing

  88. Circularly moving sum

  89. Crazy Librarian's Amazing Sorting System
  90. The forbidden built-in
  91. Real base conversion

  92. Those Greedy Romans!

  93. Let's do some location arithmetic!

  94. Find All Distinct Gozinta Chains
  95. Leyland Numbers
  96. Pascal's Alternating Triangle

  97. Can even numbers become prime?

  98. Find prime gaps
  99. Print N Squared

  100. Smallest multiple being run of 9 followed by optional run of 0