Ask your selected audience member to select a two-digit odd number in which both digits are different and to concentrate on that number. Make sure that the audience member doesn't tell you the number.
Write down your prediction on the pad of paper. Alternatively, you can write down the number ahead of time before the person has even selected a number and say that you are writing down a prediction. The difference is that one appears to be a trick where you predict the future, and in the other you read the person's mind.
Write down the number 37 on your pad of paper. Your selected audience member may not actually choose the number 37, but it is overwhelmingly the most often selected number that meets the criteria.
Ask the person to say their number out loud and then reveal your prediction by showing the audience your paper. If the person doesn't select 37, say that you aren't on the same psychic wavelength. Don't reveal your prediction--if you do, you can't do the trick again. But if you don't reveal it, ask someone else in the audience to try.
Use another numbers trick later that is more math-based and guaranteed to work. Math-based numbers tricks are often easy to spot, but if you mix them in with other tricks (especially other numbers tricks) they can be very exciting.