OK, let's crack this. We're given 48 and our task is to multiply it by 18. Essentially, we'll be adding 48 to itself 18 times.
Step 1: 0 + 48 = 48
Step 2: 48 + 48 = 96
Step 3: 96 + 48 = 144
Step 4: 144 + 48 = 192
Step 5: 192 + 48 = 240
Step 6: 240 + 48 = 288
Step 7: 288 + 48 = 336
Step 8: 336 + 48 = 384
Step 9: 384 + 48 = 432
Step 10: 432 + 48 = 480
Step 11: 480 + 48 = 528
Step 12: 528 + 48 = 576
Step 13: 576 + 48 = 624
Step 14: 624 + 48 = 672
Step 15: 672 + 48 = 720
Step 16: 720 + 48 = 768
Step 17: 768 + 48 = 816
Step 18: 816 + 48 = 864

So, 48*18 = 864