Math Mastery Challenge – Join the BMS Academic A-Team and Excel! 2026

To determine the value of √81 * √4, we first need to simplify each square root separately.

The principal square root of 81 is 9, because 9 * 9 = 81. Similarly, the principal square root of 4 is 2, since 2 * 2 = 4.

Now, we can multiply these two results together:

9 * 2 = 18.

This calculation demonstrates that the value of √81 * √4 is indeed 18.

Using the property of square roots that states √a * √b = √(a * b) also confirms this. If we apply it here:

√81 * √4 = √(81 * 4) = √324.

Calculating √324 also results in 18, since 18 * 18 = 324. This consistent value reinforces that 18 is the correct answer.