Free mental math game online: sharpen your arithmetic
OpGlyph is a free mental math game you can play online every day. You're given numbers and blank operator slots. Your job is to figure out which operators (+, −, ×, ÷) go where to hit a target result. Think of it like a maths puzzle crossed with Wordle.
What is OpGlyph?
OpGlyph is a daily arithmetic puzzle. You see a row of numbers with question marks between them, plus a target number you need to hit. The digits are fixed. Your job is to fill in the operators.
The twist is the feedback system. After each guess, you see which operators are correct (green), which exist but are in the wrong slot (yellow), and which aren't used at all (gray). It turns mental math into a logic puzzle.
How to play
The rules are simple:
1. Fill in the operators
Tap each blank slot and choose +, −, ×, or ÷. The numbers are already given. You're just deciding what operations connect them.
2. Press Enter to submit
Once you've filled all slots, hit Enter. This uses one of your 6 tries and shows feedback for each operator.
3. Use the feedback
Green means right operator, right slot. Yellow means that operator is used but in a different position. Gray means it's not in the solution.
The left to right rule
This is the key thing that trips people up at first: OpGlyph evaluates strictly left to right. There's no order of operations (BODMAS/PEMDAS). No brackets.
Once you internalise this, the puzzles click. You're just chaining operations one after another, reading from left to right. It's simpler than normal arithmetic in some ways.
Three difficulty modes
OpGlyph has Easy, Medium, and Hard modes. Each is a different puzzle for the day.
Easy (2 operators)
Only 2 blank slots. There are only 16 possible combinations (4 operators × 4 operators), so you can often solve it in 2 to 3 guesses.
Medium (3 operators)
64 possible combinations. The feedback becomes more important. Usually solvable in 3 to 4 guesses with good strategy.
Hard (4 operators)
256 combinations. Now you really need to pay attention to the feedback. Using the elimination process is essential.
Strategy tips for mental math puzzles
Here's how to solve OpGlyph puzzles more efficiently:
Start with a variety
Your first guess should use different operators if possible. Something like + × − tells you more than + + +.
Eliminate grays immediately
If an operator comes back gray, stop using it. It's not in the solution at all. This can cut your options dramatically.
Move yellows around
Yellow means right operator, wrong slot. Try it in a different position next guess. Lock in greens and shuffle yellows.
Calculate before submitting
Do the mental math first. Make sure your guess actually hits the target before you waste a try on something that doesn't work.
Why play a daily mental math game?
Mental arithmetic is like any skill: it gets rusty if you don't use it. A quick daily puzzle keeps those neural pathways active without requiring a big time commitment.
OpGlyph specifically trains a few things: basic arithmetic fluency, sequential processing (working left to right), and logical elimination (using feedback to narrow options). It's a genuine mental workout disguised as a game.
The daily format helps too. One puzzle a day means it's sustainable. You're not grinding through hundreds of problems. Just a quick rep each morning to keep your arithmetic sharp.
Benefits of mental math practice
Regular mental math practice has some real benefits beyond just being better at arithmetic:
Faster everyday calculations
Splitting bills, calculating tips, estimating costs. Mental math makes these quicker and you stop reaching for your phone calculator.
Better number sense
You develop an intuition for whether answers "feel right." This helps catch errors and makes you more confident with numbers generally.
Working memory exercise
Holding numbers in your head while you calculate trains working memory. This has benefits beyond just maths.
OpGlyph vs other math games
There are lots of math games out there. Here's what makes OpGlyph different:
I built OpGlyph because most mental math apps felt either too simple (just timed arithmetic drills) or too complex (elaborate game mechanics that distract from the maths). OpGlyph sits in the middle: pure arithmetic with just enough puzzle structure to make it interesting.
Play OpGlyph now
Today's puzzle is ready. See if you can find the right operators in 6 guesses.
More free daily puzzles
OpGlyph is part of the GlyphVerse, a collection of free brain training games. If you like mental math, you might also enjoy:
NumberGlyph
A daily number puzzle. Guess the secret number using logic and mathematical clues. Like Wordle but for digits.
Play →MultiGlyph
Times table drills. Quick fire multiplication practice to sharpen your recall. Great paired with OpGlyph.
Play →HieroGlyph
A code cracking puzzle. Deduce what each glyph equals using equations. Pure logical deduction with numbers.
Play →Questions or feedback? DM me on X @numberglyph.