Here's how to get there:

1. Move the decimal point to the right until you have a number between 1 and 10. In this case, you need to move it 5 places to the right to get 3.4.

2. Count the number of places you moved the decimal. This number becomes the exponent of 10. Since we moved the decimal 5 places to the right, the exponent is -5.

3. Write the number in the form a x 10^b, where 'a' is the number between 1 and 10 and 'b' is the exponent.