Answer:
1.23 * 10^-7
Step-by-step explanation:
For decimals smaller than 1 usually something like 0.0000111 you count the decimal places backwards until you get to something greater than 0. So if you have 0.0022 the exponent would be 2.2 * 10^-3
For your problem 0.000000123
There's 6 zeros before you encounter the number thus your exponent is 1.23 * 10^-7
Here's a picture of how to do it!
