How do you write 1.234 x 10^5 in standard notation?
Depending upon your definition of "standard notation", probably the answer you are looking for is:
Some people use the term "standard notation" as a synonym for "scientific notation". In this case the number
However, you will also find the term used to mean what we might think of as common notation. The answer given above is in this form.
Check with your instructor as to the meaning he/she is using.