I am a six digit number. Two of my digits have the values 300 and 4000. All the digits in my thousands are the same. The remaining digits are also the same and their sum is the 10.

nn43xx

if all the thousands are the same,
4443xx
If x+x=10, x=5, so

444355

To find the six-digit number that satisfies all the given conditions, we can follow these steps:

Step 1: Start with the given information:
- Two of the digits have the values 300 and 4000.
- All the digits in the thousands are the same.
- The sum of the remaining digits is 10.

Step 2: Let's find the value of the thousands digit.
Since all the digits in the thousands are the same, we need to find a number that has a digit value of 300 or 4000. Since we are looking for a six-digit number, the digit with the value of 4000 is not possible, as the maximum value for a single digit is 9. Thus, the digit with the value of 300 must be in the thousands place.

Step 3: Find the remaining digits in the number.
Since we know the digit in the thousands place is 3, and the sum of the remaining digits is 10, we need to find two digits that sum up to 7. The only possible combination satisfying this condition is 3 and 4.

Step 4: Find the arrangement of the digits.
Since the thousands digit is 3, the only remaining arrangement for the other digits is 3, 4, 4, 3. Thus, the final arrangement is 334,340.

Therefore, the six-digit number that satisfies all the given conditions is 334,340.