1.275 x 10 to the second power
In scientific notation, you move the decimal place until you have a number between 1 and 10. Then you add a power of ten that tells how many places you moved the decimal. In scientific notation, so 127.5 becomes 1.275 x 10 to the second power.
Source: https://www.infoplease.com/math-science/mathematics/numbers-formulas/scientific-notation