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
Train your brain with timed arithmetic challenges
Practice mental arithmetic with customizable operators and digit count. Timed rounds, score tracking. Works offline. Improve your brain speed.
Generate printable math worksheets for addition, subtraction, multiplication, and division. Choose difficulty and number of problems. Answer key included.
Complete a 10x10 multiplication grid against the clock. A fun way to master times tables.
Scroll through thousands of pre‑computed digits of π. Search for a specific string of digits. For math lovers.
Random shapes appear; compute the area mentally. Multiple choice. For middle schoolers.
Evaluate the Gamma function for real and complex inputs (real part). Extension of factorial. Academic mathematics tool.
Calculate the area of an irregular polygon by entering its vertex coordinates. Uses the shoelace formula. Pure math.
Convert between scientific notation (a × 10^n) and decimal form. Also supports engineering notation. Instant, local.
Enter two names and get a playful love compatibility percentage. Purely for entertainment! All calculation happens instantly in your browser.
Answer a series of deliberately confusing and trick questions. Lives system and funny wrong answers. Playful, no data stored.
Estimate make probability of a putt based on distance and skill rating. For disc golf enthusiasts. Fun statistical tool, no data upload.
A collection of clean, family‑friendly riddles with a reveal‑on‑click answer. Random riddle each time. Perfect for break time.
Determine what score you need on your final exam to achieve your target overall grade. Enter current grade, weight, desired grade. Local only.
Calculate output voltage from a two-resistor voltage divider. Enter input voltage and resistances to see Vout. Includes circuit schematic. No data sent.
Calculate the total resistance of up to 10 resistors in parallel. Enter values and see the combined resistance instantly. Local electronics helper.
Calculate odds of drawing specific cards or poker hands from a standard deck. Learn combinations. Local math.
Draw perfect ellipses by dragging focal points and a point on the curve. See the equation update dynamically. Educational.
A kanji appears; you guess how many strokes it has. Learn stroke order awareness.
Compute probability for simple events, as well as permutations and combinations (nPr, nCr). Useful for statistics and game theory. Browser-based math.
Type a number and see its full English word representation (e.g., 123 → one hundred twenty‑three). Supports large numbers.
Convert guinea pig age to approximate human years. Cute facts included. For guinea pig lovers. 100% local.
Peer into the virtual crystal ball to get a randomly generated, absurdly specific fortune. A fun start to your day.
Type a word and see if it can be spelled using chemical element symbols. Geeky custom message creator. Copy or share.
Convert a numeric amount into English words, perfect for writing checks or legal documents. Supports USD/GBP styles.
Try to draw a perfect circle freehand. Score based on roundness. Fun and addictive. No data sent.
Calculate ideal stereo speaker placement (toe-in, distance from wall) for best soundstage. Visual diagram. For audiophiles. Local tool.
Translate hexadecimal numbers to decimal integers. Instantly see the magnitude. A simple, private utility for developers and mathematicians.
Enter a year to check if it is a leap year. Shows the rule explanation and next/previous leap years. Simple reference.
Convert across length, mass, speed, temperature, data, and more. Search any unit and type. Compact and fast.
Select a destination language and generate a printable mini phrasebook with essential greetings, directions, food, and emergency phrases. Local only.