ecech.

Tools tagged #math

Every ecech. tool tagged math: 23 free calculators and utilities across Developer & Code, English Exams & Writing. No signup, runs in your browser.

📊

Attendance Calculator

Every absence raises the number of future sessions needed to recover, because the denominator grows alongside the numerator.

Math
💻

Base Converter

\u22125 is 11111011 in 8 bits and 11111111111111111111111111111011 in 32. Neither is more correct — the width is part of the answer.

Developer
📊

Compound Growth

Percentages multiply, they do not add. Apply a sequence of changes and see where you actually end up, including what it takes to recover a loss.

Math
📊

Decimal to Fraction

Putting the digits over a power of ten is exact and useless. Continued fractions find the simplest fraction that is close enough — the same method that gives 355/113 for π.

Math
📊

Final Grade Calculator

What do I need on the final to pass? Says plainly when a target is out of reach, and shows the whole range of outcomes rather than one number.

Math
📊

Fraction Calc

Fractions are exact and decimals are not. This keeps integers all the way through and only rounds when it prints.

Math
💬

GPA Calculator

Unweighted caps at 4.0, weighted goes to 5.0, plus/minus reaches 4.3. And a GPA is credit-weighted, so averaging the grades directly is wrong.

English
📊

Grade Recovery Path

Translate earned points and remaining weight into a required future average.

Math
📊

Mean Median Mode

All three centres at once, with the working shown and a distribution plot that makes it obvious when they disagree — which is exactly when the average is misleading you.

Math
📊

Missing Data Range

Compute best and worst feasible means from declared value bounds rather than one imputed guess.

Math
📊

Percent of Total

Three equal parts are 33.3% each, which sums to 99.9. Rounding each value correctly does not fix it. Largest-remainder allocation does.

Math
📊

Percentage Calc

Three different questions share the word percentage, and a fall is never undone by a rise of the same size.

Math
📊

Percentage Change

Four related questions in one place — change between two numbers, apply a percentage, find the original, and see the working written out so you can check it.

Math
📊

Percentage Error

Same two numbers, same gap of 50. The answer depends entirely on which one you divide by — which is why the choice has to be justified.

Math
📊

Pooled Standard Deviation

Weight sample variances by their degrees of freedom instead of averaging standard deviations.

Math
📊

Probability to Odds

Translate a percentage probability into odds for and odds against.

Math
📊

Progress ETA

A progress bar extrapolates from the last instant. Measuring over a longer window is the whole reason a manual estimate is better.

Math
📊

Randomization Plan

Allocate participant IDs across arms inside blocks while preserving exact counts and audit order.

Math
📊

Reverse Percentage

The sale price is £80 after 20% off — what was it before? Not £96. Adding a percentage back is not the same as taking it off, and this shows why.

Math
📏

Roman Numerals

Only I, X and C can be subtracted, and only from the next two symbols up. That single rule is why so many hand-written numerals are wrong.

Converters
💰

Split the Bill

100 divided by three is 33.33 each, which totals 99.99. This hands out the leftover pennies so the parts match the bill exactly.

Finance
📊

Wide to Long CSV

Turn wide repeated-measure columns into tidy variable and value rows.

Math
📊

Z-Score Percentile

Show left-tail percentile, upper tail and two-sided tail from one standard-normal z-score.

Math

Related tags