what is the least 4-digit number you can make with the digits 2, 4, 3, 1?

1234

If you indeed use all 4

but if that is not specified then
1111

To find the least 4-digit number you can make with the digits 2, 4, 3, 1, you need to arrange these digits in ascending order.

Step 1: Start by identifying the smallest digit. In this case, it is 1.

Step 2: The next smallest digit is 2.

Step 3: The next smallest digit after 2 is 3.

Step 4: Finally, the largest digit is 4.

Now, combine these digits in the determined order to form the least 4-digit number: 1234.

Therefore, the least 4-digit number you can make with the digits 2, 4, 3, 1 is 1234.