The mole triangle is a simple way of visualizing how to convert the numbers
given to you.

e.g.: Lets say your given 2.00g of H2O
and want to find out the number of moles (mol) present.

To
get from g àmol you have to use the equation: g / molar mass = moles

The reason you have to divide the g by the molar mass and NOT multiply
is because you are moving up the triangle.

Note: Whenever you move UP the triangle on either side you divide, when you
move DOWN the triangle you multiply.

In this equation your given g so you can fill in part of your equation right
away:

2.00g of H2O / molar mass = moles

Next you have to find your molar mass. On your periodic table the atomic mass
of each element is written down, well molar mass is the total mass of the elements youre given. In this case you have H2 and O. An easy way to do the molar mass is to show your work like this:

H2: 1g X 2 = 2g

O: 16g

2g + 16g= 18g/ mol

Next you have to put your molar mass into your equation:

2.00g of H2O / 18g/ mol = mol

Now you can divide your g by your molar mass to find your moles:

2.00g of H2O / 18g/ mol = .11mol of H2O