Felix says that 2,000 + 400 + 70 is another way to write 2,407. What is Felix's error

Felix's error is that he added the numbers incorrectly.

Felix got the answer 2,407 by adding 2,000 + 400 + 7, but the problem states to add 2,000 + 400 + 70. In return, by adding in the correct way like the question have stated you should get 2,470

2,000 + 400 + 70 would equal 2,470.

The correct way to write it would be 2,000 + 400 + 7