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 a sheet of random arithmetic problems (+, -, Γ, Γ·) with configurable digits. For kids and brain training.
Complete a 10x10 multiplication grid against the clock. A fun way to master times tables.
Click cells to see patterns, highlight multiples. Visual way to learn multiplication. Print empty grid.
Listen to two notes and identify the interval. Purely local Web Audio synthesis. Sharpen your relative pitch.
Enter a decimal number and see detailed stepβbyβstep conversion to binary, octal, and hex. For students.
Type a mathematical expression like 'sqrt(16)+sin(pi/2)' and get the result instantly. Supports popular functions. Local.
Drag pie slices to represent fractions and see them added together. Great for visual learners.
Random shapes appear; compute the area mentally. Multiple choice. For middle schoolers.
Determine what score you need on your final exam to achieve your target overall grade. Enter current grade, weight, desired grade. Local only.
Enter number of eyelet pairs and lacing style to find the correct shoelace length in inches/cm. Never buy too short.
Test how fast you can convert between binary and decimal. Timed drills with increasing difficulty. Learn baseβ2 fluency.
Create custom flashcards and review them with a simple spaced repetition algorithm. Data stored in your browser. No sign-up required.
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.
Enter pins per roll and calculate total bowling score including strikes and spares. Supports 10 frames. Learn scoring rules visually.
Calculate the area of an irregular polygon by entering its vertex coordinates. Uses the shoelace formula. Pure math.
Calculate board feet for dimensional lumber and generate a cut list with waste factor. Quick carpentry tool.
Drag colored shapes to matching outlines. Simple, no-text game for 2-4 year olds. Works on touch devices.
Draw perfect ellipses by dragging focal points and a point on the curve. See the equation update dynamically. Educational.
Calculate the total resistance of up to 10 resistors in parallel. Enter values and see the combined resistance instantly. Local electronics helper.
Apply a color tint overlay over text to see if it helps reading comfort. Trial for visual stress.
Enter roof line or tree height and get the length of light strings needed. Estimate power draw.
Convert annual salary to effective hourly rate considering holidays, vacation, and work hours per week.
Estimate make probability of a putt based on distance and skill rating. For disc golf enthusiasts. Fun statistical tool, no data upload.
Check if your A/B test results are statistically significant using chi-squared test. Enter visitors & conversions for control/variant. Results in plain English.
Type a word and see if it can be spelled using chemical element symbols. Geeky custom message creator. Copy or share.
Select tuning, scale length, and string gauge to calculate total tension on the neck. Build custom string sets.
Calculate the amount of wax, fragrance oil, and dye for silicone mold cavities. Perfect scent throw.
Peer into the virtual crystal ball to get a randomly generated, absurdly specific fortune. A fun start to your day.