Fractional notation is a form that non-whole numbers can be written in, with the basic form a/b. Fractional notation is often the preferred form to work with if a calculator is not available.
There are two general forms that non-whole numbers can be written in: fractional and decimal. For decimal notation, any part of a number is simply written after the decimal. For example, 9/2 is equal to 4.5, where 0.5 is the non-whole part left over. Numbers in decimal form can be added directly to each other in all situations, while fractions can only be added to each other directly if they share a common denominator.