Teach the basics of counting. This is more than learning to count from one to 100. You can also use a number chart to teach counting by 2s, 3s and other numbers. For example, you can learn to count by 2s by looking at the chart, starting with two, and skipping to every other number.
Teach the basics of addition and subtraction. Instruct a student to start with a number and then to add or subtract another number. If the student starts with 27 and subtracts three, he can count backwards three numbers from the 27 to arrive at 24. This acts as a precursor to teaching a student how to do math in his head.
Understand the relationship of one number to another. For example, one day you might teach a student about what every tenth number has in common. The student can look down a column to see how the numbers look similar and can hear the name to see how they sound in relation to each other. The same is true for other relationships, such as every third number. The student can clearly see how the patterns repeat.
Teach a student the basics of multiples after teaching him to count by numbers. For example, when a student learns to count by 2s, he might notice that all of these numbers end in two, four, six, eight or zero. These, you can teach him, are multiples of 2 because they are divisible by the number two.