Mental Math Trainer - Online Timed Arithmetic Drills
Practice mental arithmetic with customizable operators and digit count. Timed rounds, score tracking. Works offline. Improve your brain speed.
UD5 Toolkit
Practice mental arithmetic with customizable operators and digit count. Timed rounds, score tracking. Works offline. Improve your brain speed.
Solve random arithmetic problems under a time limit. Track your score and improve mental calculation. No data collected.
Generate a sheet of random arithmetic problems (+, -, ×, ÷) with configurable digits. For kids and brain training.
Create custom flashcards and review them with a simple spaced repetition algorithm. Data stored in your browser. No sign-up required.
Complete a 10x10 multiplication grid against the clock. A fun way to master times tables.
Play random Morse characters at configurable speed. Learn with Koch or Farnsworth method.
Spin a wheel to assign weekly chores to children. Customizable tasks. Ends arguments.
Type a passage and see it appear in a realistic cursive font. Helps connect handwriting to digital text.
Hear a word spoken by browser TTS and type the spelling. Choose difficulty or paste your own list. Great for kids. Local only.
Generate and print custom calligraphy practice sheets with adjustable x-height, slant angle, and base line. Perfect for copperplate or Spencerian.
Randomly generated subnetting questions. Calculate network address, broadcast, and usable range. For CCNA prep.
Use your keyboard or mouse as a straight key. Hear the tone and see the dots/dashes. Perfect for learning CW. Local.
Format a list of Q&A pairs and export as a CSV ready for Anki import. Simple line‑based template. Local.
Calculate BMI for children and teens (ages 2‑19) and see the percentile based on CDC growth charts. Educational only.
Generate a random HTML/CSS card with different box model properties. Inspect and guess the size. For learners.
Get a random, clean, and silly joke perfect for children. Guaranteed giggles. No offensive content.
Get an endless supply of clean, family‑friendly knock‑knock jokes. Click for a new one. No ads, just laughs.
Enter a mathematical function for dx and dy and see the vector field arrows. Perfect for studying differential equations.
Check if a number of the form 2^p‑1 is a Mersenne prime. Quick Lucas‑Lehmer test simulation for small p.
Enter any integer and quickly find the next prime number after it. Perfect for hashing and puzzles.
Set a 20, 30, or 45‑minute countdown to simulate a technical interview. Hidden/unhidden. Boost your prep.
Practice sending Morse code using a virtual straight key. Visual feedback and audio tone. Learn timing and proper fist.
Shows a random short word and displays animated ASL fingerspelling letters. Type what you see. Improve receptive skills.
View thousands of digits of Euler's number (e). Click to copy a block. For math enthusiasts.
Scroll through thousands of pre‑computed digits of π. Search for a specific string of digits. For math lovers.
Generate magic squares of odd order (3x3, 5x5, …). See the sum constant and verify rows, columns, diagonals. Educational math toy.
Generate the Koch snowflake fractal to a desired iteration level. See how the perimeter grows. Interactive geometric art.
Plot one or more mathematical functions f(x) on a 2D canvas. Zoom, pan, and see intersections. Great for calculus and algebra. Purely client‑side.
Enter text and generate the corresponding Morse code audio beeps. Adjust speed and tone. Great for learning and practicing CW. No download.
Compute probability for simple events, as well as permutations and combinations (nPr, nCr). Useful for statistics and game theory. Browser-based math.