OK, let's crack this. We're given 869 and our task is to multiply it by 12. Essentially, we'll be adding 869 to itself 12 times.
Step 1: 0 + 869 = 869
Step 2: 869 + 869 = 1738
Step 3: 1738 + 869 = 2607
Step 4: 2607 + 869 = 3476
Step 5: 3476 + 869 = 4345
Step 6: 4345 + 869 = 5214
Step 7: 5214 + 869 = 6083
Step 8: 6083 + 869 = 6952
Step 9: 6952 + 869 = 7821
Step 10: 7821 + 869 = 8690
Step 11: 8690 + 869 = 9559
Step 12: 9559 + 869 = 10428

So, 869*12 = 10428