Express 1.51 in Different Number Representations

To solve this problem, we must convert the decimal number $1.51$ into a mixed number.

Step 1: The given number $1.51$ consists of a whole number part and a decimal part. The whole number part is 1.

Step 2: The decimal part $.51$ can be expressed as a fraction. Since $.51$ means 51 hundredths, we write it as $\frac{51}{100}$.

Step 3: Combine the whole number part (1) and the fractional part ($\frac{51}{100}$) to express the decimal as a mixed number:

$1.51 = 1\frac{51}{100}$.

Therefore, the solution to the problem is $1\frac{51}{100}$.