How to use Google for math calculations

Aside from the familiar specialized searches Google can perform, such as those for images, mapping and news, it also can provide more useful -- if obscure -- functions if you know a few tricks.

1. Calculate. In the search window, type in math problems (e.g. 678+225), hit enter. Use no spaces between numbers and symbols. Use a plus sign (+) to add, dash (-) to subtract, asterisk (*) to mul- tiply, slash (/) to divide. You can do a string of numbers using multiple functions (e.g. 24*2/8-3).

2. Time. To find out the current time anywhere in the world, in the search window type in "what time is it" followed by a space and the location. For example, the time in Hong Kong would be: what time is it Hong Kong

3. File type. If you are searching the Web for a specific type of file (e.g. PDF, JPG, MP3 or DOC files), in the search window type in "filetype: filetypename" followed by a space and your search term. For example, a search for PDF files on asparagus would be: filetype: pdf asparagus.