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These numbers are often of a different color and are offset from the main symbol on the key. The typical locations for these numbers are on the m, j, k, l, u, i, o, 7, 8, and 9 keys. Some keyboards without number pads still have number lock keys, which are often labeled “NumLk”. Otherwise, look for a key that matches the color of the hidden key-number, usually labeled “FN” key. Hold FN and press the scroll lock key, or just hold FN, depending on the computer, to enable the number pad function. You may need to hold both FN and ALT at the same time to enter the code. A full list of codes is at http://fsymbols.com/keyboard/windows/alt-codes/list/. Release the ALT key and the symbol will appear. If your keyboard has a number pad on it, this is a much simpler process. Ensure Num Lock is enabled, then just hold alt, enter the code on the number pad, and receive your symbol. This goes for any PC keyboard with a number pad, whether it is a laptop or a desktop. Examples include general symbols like ALT + 1, ☺, or ALT + 12, ♀. The system can also create accented letters such as ALT + 0193, Á, or general foreign characters, like ALT + 0223, ß. Mathematical symbols, such as ALT + 0177, ±, and a few fractions like ALT + 0190, ¾, are also possible.

Summary:
Check for small numbers on certain keys. Enable the number pad function. Hold the ALT key and enter the code. Create a symbol with a number pad.