Answer:
6.234 x 10^-7
Explanation:
When writing the number in standard form you have to look at the decimal point. If you already have a decimal point (like the question) then look for the first non-zero digit (in terms of the question, its 6). You have to move the decimal point to right until its after the first non-zero digit. Count how many spaces you moved, in this case its 7. If you are moving to the left you have to put a negative sign when writing the power of 10.
Hope this helps!!