Math Tools and Calculators

Here are some really useful applications to speed your way to that all-important solution.

Numbers

Enter two numbers, and see not only the percentages, but how they are calculated.
Convert between Binary, Decimal and Hexadecimal. Can handle fractions and negatives.
Want to know if a number is Prime? Or if not, which prime numbers are it's factors?
Find all the factors of a number
Find if two numbers are coprime (if they share anyprrime factors)
Enter formulas such as (3+2/9)^2 or sin(1/5), has history and even a slider for an "a" value.
Accepts formulas such as (3+2/9)^2 or sin(1/5) and you can also click on a keypad.
Can convert from/to Roman Numerals. What year was MDMCLXXI ?
Find the greatest common factor of 2 or 3 numbers. Useful for simplifying fractions.
Find the least common multiple of 2 or 3 numbers. Useful for adding or subtracting fractions.
Calculate answers to full precision. Want to multiply to hundreds of digits of accuracy? Done!
Enter the formula, see the result.
Find the right amounts of a mixture.
Converts Decimals to Fractional form, showing steps.
Calculate Combinations and Permutations

Measure

A neat yet powerful Unit Converter. Can convert length, mass, volume, temperature and more. Hundreds of imperial and metric units are supported
Calculate the day of the week for any date between 1582 and 4902

Algebra

Do matrix calculations such as Determinant, Inverse and Multiplication
See what happens when you sum up a series of functions.
Convert between magnitude/angle and x,y. Add vectors. Dot product.
Have an equation like "ax2 + bx + c = 0"? We can solve it!
You can plot two functions together, and even save the results as a web link.
Graph equations like "x2+y2=2"
Plot an f(x,y) style function like x^2-y^2

Geometry

Calculate the areas of common shapes such as triangles, circles and ellipses
Spin, explode and see the nets of over 100 polyhedra.
Calculate the volume, area, diamter and radius of a sphere
If you have two points and need to know the straight line formula (y=mx+b) that connects them.
Calculate side length, area, diagonal or perimeter of a square.
Calculate width, height, area, diagonal or perimeter of a rectangle.

Data

Shows you the results at every stage of the calculation
Print or save graph paper

Sets

Union, intersection and difference of two sets

Money

Its a game, but also useful for adding up money.

Other Cool Stuff

Spiral Artist
Symmetry Artist
Tessellation Artist
General Drawing Tool

A simulation of how suns, planets, moons, etc behave under the influence of gravity
Explore the interesting "interference patterns" created by overlapping grids, lines, etc
Try your estimation skills