To solve this problem, you need to understand place value concepts. Each digit added makes a number greater, but when adding numbers you have to make sure that you add your other digits in the right places.
To solve 20,000 + 70 + 3, first we can add 70 + 3. This may seem like a simple problem, but it is a good example of place values. Because 3 is in the ones place, you add it to the ones place of the other number (currently a 0). 3 + 0 = 3, so you replace the digit 0 with a 3, giving you the answer 73.
Now, we must solve 20,000 + 73 in a similar manner. Because 73 takes up the tens and the ones places, we should add these numbers to the preexisting digits in those values. Because they are zeros, your answer will still be 73, making your final answer 20,073.
Hope this helps!
