Digit

A digit is a single whole non-negative number (0 to 9).
For example, the number 432 has 3 digits. Each digit has a place value. In the number 432, the 2 is the number of ones in the number.

The 3 is the number of tens in the number, and the 4 is the number of hundreds in the number. So you can add them up, like this:

4 X 100 =	400
3 X 10 =	30
2 X 1 =	2
	---
	432

Now here's a problem for you: What is the tens digit in the number 5678?