The standard form if 10,000+20+3

The answer is 10,023 or 10023

You basically start off with the largest number 10,000 and then fill in the 0's with the proper digits. In this case, the last two zeros turn into 2 and 3 (in that order) because of the 20 and 3 at the end. Since there is no thousands value or hundreds value, we leave the second and third zeros as they are.