When entering numbers into a spreadsheet, you sometimes need to ensure that the number format is consistent. For example, if the numbers in question represent prices, you may want to display a currency symbol or you may simply want to make sure that the number of decimals displayed is consistent..

Unless the user specifies otherwise, all numbers in Excel are rendered in the “General” format. What this means is that numbers are displayed exactly as one enters them: if you enter two decimals, two decimals are displayed; if you went to one decimal, one decimal is displayed; and so forth.

When specifying the number format, the best idea is usually to select the whole column. To do this, click on the letter or letters representing the column. (Any text contained in the selection will not be affected by the number format you specify.)

Number formats are displayed in the “Numbers” section of the Home Tab of the Ribbon. There are three main formats related to numbers: the first is called “Number”, the second “Currency” and the third “Accounting”. To gain access to the full range of number formats, choose “More Number Formats” from the drop-down menu. Another way of accessing the same dialog box is to click on the launch button in the “Numbers” section of the Home Tab.

When you click on one of the number formats on the left of the “Numbers” dialogue box, you are given a series of choices which enable you to refine the way that the format will work. Thus, if your numbers refer to an hourly rate, you would click the “Number” category in the left column and then specify two decimal places. The option to “Use Thousands Separator” will add the appropriate separator to demarcate thousands. The separator used will depend on your locality: for example, in the UK or USA, a comma will be used; in European countries, a dot will be used.

The last option in the “Number” category controls the display of negative numbers. The default setting is to display a minus sign in front of the number and leave the colour of the text unchanged. However, you can also choose not to display the minus sign and change the colour of negative numbers to red. Alternatively, you can change the colour of negative numbers to red and also display the minus sign.

When we click the “Currency” category, we have pretty much the same choices with the addition of the currency symbol. We can specify which currency symbol is used or we can dispense with the symbol altogether.

The “Accounting” category is almost identical to “Currency”. Once again, we can choose the currency symbol. However, you will notice that there are no choices relating to negative numbers. The convention in accountancy is to put negative numbers in brackets.

As well as using the number dialog box, you’ll notice a series of handy buttons which can apply each of the number formats with one click. There are also a couple of buttons for increasing and decreasing the number of decimals displayed in the selected cells.

Finally, there may be times where you enter a number into a cell but do not want Excel to treat it as a number. For example, if you have a column of data representing an ID, although the ID may be numeric, you may not want Excel to regard it as a number or to modify it in any way. You will probably want it to simply stay exactly as it was entered. Whenever that’s the case, it’s best to format the number as “Text”. The simplest way of doing this is to highlight the appropriate column and in the number dialog box choose “Text” as the category.