Let's roll up our sleeves and solve this. We have 987 and we're going to multiply it by 11, essentially adding 987 to itself 11 times.
Step 1: 0 + 987 = 987
Step 2: 987 + 987 = 1974
Step 3: 1974 + 987 = 2961
Step 4: 2961 + 987 = 3948
Step 5: 3948 + 987 = 4935
Step 6: 4935 + 987 = 5922
Step 7: 5922 + 987 = 6909
Step 8: 6909 + 987 = 7896
Step 9: 7896 + 987 = 8883
Step 10: 8883 + 987 = 9870
Step 11: 9870 + 987 = 10857

So, 987*11 = 10857