In the example above, the number 3 appears in cell B5 and the number 100 in cell C5. To multiply the two numbers together, we need to reference each cell i.e. B5 x C5.
The equals sign is always used at the start of a spreadsheet formula. * is used to indicate multiplication and no spaces are used, so the formula to multiply one number one cell by the other (from the picture above) is =B5*C5.
If this formula is typed into cell D5, followed by Return, the answer (300) will appear in cell D5.