The expression "2 × 171" represents a multiplication problem where the number 2 is multiplied by 171. Multiplication is a basic arithmetic operation that combines equal groups. In this case, it means adding the number 171 to itself once. When you calculate "2 × 171," the result is 342. This means that if you have two groups of 171, the total amount is 342. This concept is fundamental in mathematics and is used in various applications, from simple counting to more complex calculations in fields like science and finance.