To compare the two numbers 21.208 and 21.28, we can look at their decimal representations:
- 21.208 (which has three digits after the decimal point)
- 21.28 (which has only two digits after the decimal point, but is equivalent to 21.280)
Now, comparing the two:
- The first three digits after the decimal point of 21.208 are 208.
- The first three digits after the decimal point of 21.280 are 280.
Since 208 is less than 280, we can conclude that:
21.208 < 21.28
So the correct symbol to make the statement true is "<".
The answer is: <