Write the next sentence in this paragraph:

How to quickly multiply single digits by 9 
Remember that any number multiplied by 1 is the number itself. 
No matter how tricky 9 is, it can't escape the fact that 1x9 will always equal 9. 
Start simple and work your way up.

Choices: 1). If you're almost certain you know what you're doing, just jot down whatever you can think of. Unless your calculations yourself require that you write them down first.; 2). Work your way up to 17 and you won't have a single digit. This will cause less confusion later! Remember that most cell phones only have 14 digits.; 3). Don't try to multiply 9x9 before you learn 9x2 because it is a lot easier to think of math like a ladder. You should take each step to the top because if you try to skip steps you may just fall back and have to start over.; 4). You are at half the difficulty, meaning not even you can make the math as simple as you want it to be. In addition, there's a good chance that, once you understand fractions, you'll be able to figure out how to solve higher 9's with less work.;
3).