Alright, let's solve this math problem step by step. First, we have the number 407. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 10. So, we're going to take the number 407 and add it to itself 10 times.
Step 1: 0 + 407 = 407
Step 2: 407 + 407 = 814
Step 3: 814 + 407 = 1221
Step 4: 1221 + 407 = 1628
Step 5: 1628 + 407 = 2035
Step 6: 2035 + 407 = 2442
Step 7: 2442 + 407 = 2849
Step 8: 2849 + 407 = 3256
Step 9: 3256 + 407 = 3663
Step 10: 3663 + 407 = 4070

So, 407*10 = 4070