Alright, let's solve this math problem step by step. First, we have the number 631. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 18. So, we're going to take the number 631 and add it to itself 18 times.
Step 1: 0 + 631 = 631
Step 2: 631 + 631 = 1262
Step 3: 1262 + 631 = 1893
Step 4: 1893 + 631 = 2524
Step 5: 2524 + 631 = 3155
Step 6: 3155 + 631 = 3786
Step 7: 3786 + 631 = 4417
Step 8: 4417 + 631 = 5048
Step 9: 5048 + 631 = 5679
Step 10: 5679 + 631 = 6310
Step 11: 6310 + 631 = 6941
Step 12: 6941 + 631 = 7572
Step 13: 7572 + 631 = 8203
Step 14: 8203 + 631 = 8834
Step 15: 8834 + 631 = 9465
Step 16: 9465 + 631 = 10096
Step 17: 10096 + 631 = 10727
Step 18: 10727 + 631 = 11358

So, 631*18 = 11358