1. A new set of five random numbers between -20 and 20 are generated each day.
2. Use the button interface below to write a mathematical expression containing those five numbers that equals today's date.
3. Each number may only be used once. The expression must be shorter than 50 key presses. No step when solving your expression can produce a number larger than a quadrillion.
4. Achieve a higher score by using all five numbers and by using the more complex operations and functions. Try to get the highest score you can!
Rules for Scoring
+ 1 point for each of the five numbers you use in your expression.
+ 1 additional point if you use all five numbers (including the 5 points per number, that is 6 points just for using all five numbers).
+ 1 point for each time you use the exponent (^) or root (√) operation.
+ 1 point for each time you use a function UNLESS that function could be removed and your expression would equal to the same value.
Note: Some people argue that raising a number to a high power of 2 and square rooting it a corresponding amount of times is mathematically valid, and so each square root
should give you points, while others argue that the solution would be the same without this trick and that it is not very creative, so they shouldn't give you points.
Thus, as a compromise on these two ways of thinking, if your solution features of chain of many consecutive square roots, only the first 4 square roots will award you points.
Today's Date is...
Loading Date
00
Loading Numbers
Try to make today's date by combining the five orange numbers with math operations!
Input your solution with the keypad below (sometimes it helps to work it out on paper first).
Numbers:
Operations:
Functions:
Parentheses:
Including functions and operations colored in lighter purple will grant you additional points
Information on Obscure Operations & Functions
^ (Exponent Operator): The carrot (^) represents the exponent operator. To use it, place the base before the symbol and the power after, like 2 ^ 3, which will be displayed as 23.
ⁿ√x (Radical Operator): The radical operator allows the player to take the n-th root of a number. Place the power before the symbol and the base after the symbol, like 3 √ 8, which will be displayed as 3√8.
Σ (Summation Function): The summation function adds all the numbers from 1 to the input. It only operates on positive whole numbers.
Σ4 = 4 + 3 + 2 + 1 = 10
Σ6 = 6 + 5 + 4 + 3 + 2 + 1 = 21
! (Factorial Function): The factorial function multiplies all the numbers from 1 to the input. It only operates on positive whole numbers.
4! = 4 × 3 × 2 × 1 = 24
6! = 6 × 5 × 4 × 3 × 2 × 1 = 720
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Solving Steps
[This is where a step-by-step evaluation of your expression will appear]
Your Top Score Today
About this Site
DATE-O was first formulated by my middle school math teacher David Baker, an idea which I have adapted
into this site as close to the original game as possible. I am forever appreciative of him for inspiring me to
delve deeper into math with that type of self-discovery and play that this game so elegantly captures.
This marks the first website I have built, and I hope you have as much fun finding solutions as I had programming the game!