How do you write the value of a digit?

To write the value of a digit, you need to consider its position within a number. Each digit's value is determined by multiplying it by the base (10 for decimal numbers) raised to the power of its position, counting from right to left, starting at zero. For example, in the number 345, the digit '4' is in the tens place, so its value is 4 × 10^1, which equals 40.