How many codes are possible with 4 digits?
Understand the Problem
The question is asking about the total number of combinations or permutations that can be formed using 4 digits. Each digit can range from 0 to 9, giving a total of 10 possible choices for each digit position.
Answer
10000
Answer for screen readers
10000
Steps to Solve

Define the problem We need to find the total number of combinations or permutations of 4 digits, where each digit can be any number from 0 to 9. For each digit, we have 10 choices.

Calculate the possibilities Since there are 4 positions and each position has 10 choices, we can calculate the total number of combinations by raising the number of choices to the power of the number of positions.
This can be expressed mathematically as:
$$ \text{Total combinations} = 10^4 $$
 Perform the calculation Now we simply calculate $10^4$:
$$ 10^4 = 10 \times 10 \times 10 \times 10 = 10000 $$
 State the final result The total number of combinations that can be formed using 4 digits, each from 0 to 9, is 10000.
10000
More Information
In this scenario, we explored the total number of possible 4digit combinations where each digit can independently take values from 0 to 9. This leads to a total of 10,000 unique combinations. This concept is often used in areas such as computer science and cryptography.
Tips
 Misunderstanding permutations vs. combinations: Since each digit can repeat and the order matters, it’s important to correctly identify this as a permutation problem.
 Forgetting to consider all digit positions: Ensure that each of the four positions is counted in the calculations.