Yes, 81 squared is a rational number. When we square a number, we multiply it by itself. In this case, 81 squared means we calculate 81 x 81, which equals 6561.
A rational number is defined as any number that can be expressed as the quotient or fraction of two integers, where the denominator is not zero. Since 6561 can be represented as 6561/1, it meets the criteria of being a rational number.
In summary, since the result of squaring 81 is 6561 and it can be expressed as a fraction, we can confidently say that 81 squared is indeed a rational number.