Using Autosum
Autosum is probably the most common function used in Excel. A function is a type of formula that goes beyond basic arithemtic. Autosum adds up a list of numbers without you having to type in every cell reference - it is extremely useful.
It follows this basic structure: =sum(a1:a6) where the numbers to add up are in cells a1, a2, a3, a4, a5 and a6 . When making this formula you give it the first and last cells in the list of cells to add up (a1 and a6)
Want to practice? Here are links to the basuc sums sheets - just use autosum instead of typing the cells some sums to try and here's another set (use a calculator to check your answers ).