Alright, let's solve this math problem step by step. First, we have the number 426. 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 426 and add it to itself 25 times.
Step 1: 0 + 426 = 426
Step 2: 426 + 426 = 852
Step 3: 852 + 426 = 1278
Step 4: 1278 + 426 = 1704
Step 5: 1704 + 426 = 2130
Step 6: 2130 + 426 = 2556
Step 7: 2556 + 426 = 2982
Step 8: 2982 + 426 = 3408
Step 9: 3408 + 426 = 3834
Step 10: 3834 + 426 = 4260
Step 11: 4260 + 426 = 4686
Step 12: 4686 + 426 = 5112
Step 13: 5112 + 426 = 5538
Step 14: 5538 + 426 = 5964
Step 15: 5964 + 426 = 6390
Step 16: 6390 + 426 = 6816
Step 17: 6816 + 426 = 7242
Step 18: 7242 + 426 = 7668
Step 19: 7668 + 426 = 8094
Step 20: 8094 + 426 = 8520
Step 21: 8520 + 426 = 8946
Step 22: 8946 + 426 = 9372
Step 23: 9372 + 426 = 9798
Step 24: 9798 + 426 = 10224
Step 25: 10224 + 426 = 10650

So, 426*25 = 10650