Alright, let's solve this math problem step by step. First, we have the number 398. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 25. So, we're going to take the number 398 and add it to itself 25 times.
Step 1: 0 + 398 = 398
Step 2: 398 + 398 = 796
Step 3: 796 + 398 = 1194
Step 4: 1194 + 398 = 1592
Step 5: 1592 + 398 = 1990
Step 6: 1990 + 398 = 2388
Step 7: 2388 + 398 = 2786
Step 8: 2786 + 398 = 3184
Step 9: 3184 + 398 = 3582
Step 10: 3582 + 398 = 3980
Step 11: 3980 + 398 = 4378
Step 12: 4378 + 398 = 4776
Step 13: 4776 + 398 = 5174
Step 14: 5174 + 398 = 5572
Step 15: 5572 + 398 = 5970
Step 16: 5970 + 398 = 6368
Step 17: 6368 + 398 = 6766
Step 18: 6766 + 398 = 7164
Step 19: 7164 + 398 = 7562
Step 20: 7562 + 398 = 7960
Step 21: 7960 + 398 = 8358
Step 22: 8358 + 398 = 8756
Step 23: 8756 + 398 = 9154
Step 24: 9154 + 398 = 9552
Step 25: 9552 + 398 = 9950

So, 398*25 = 9950