Performing (simple) mathematical calculation in Word

Sometimes it is convenient to perform simple mathematical calculation in word.
For example, if the following text is needed to put in word file

C = 42.5/1.1 = 38.64

Instead of using calculator program we can perform calculation in word by the following steps

1. Type C = 42.5/1.1 =
2. Ctrl-F9 to create empty field (it will look like this {})
3. In {} type {=42.5/1.1}
4. F9 to update the field (word will calculate the above expression for us
   

You can copy, paste and edit the formula using the following steps

1. Copy, Paste
2. Shift-F9 to alter the formula, the change the formula or values as you like.
3. Press F9 to update the field and toggle back into text mode (now the value should be updated according to the new formula)

Note: Shift-F9 will toggle only the field you selected while Alt-F9 will toggle all fields in the file (this might be helpful if you want to see the formula in other places or to copy the formula.)