The expression "2² × 5²" involves squaring the numbers 2 and 5. Squaring a number means multiplying it by itself. Therefore, 2² equals 4 (since 2 × 2 = 4) and 5² equals 25 (since 5 × 5 = 25). Next, we multiply these two results together: 4 × 25. This gives us 100. Thus, the expression "2² × 5²" simplifies to 100. This calculation is often used in various fields, including mathematics and engineering, to demonstrate the properties of exponents and multiplication.