Without delay, let's solve this. We've got 448 and we will be multiplying it by 21, that is, adding 448 to itself 21 times.
Step 1: 0 + 448 = 448
Step 2: 448 + 448 = 896
Step 3: 896 + 448 = 1344
Step 4: 1344 + 448 = 1792
Step 5: 1792 + 448 = 2240
Step 6: 2240 + 448 = 2688
Step 7: 2688 + 448 = 3136
Step 8: 3136 + 448 = 3584
Step 9: 3584 + 448 = 4032
Step 10: 4032 + 448 = 4480
Step 11: 4480 + 448 = 4928
Step 12: 4928 + 448 = 5376
Step 13: 5376 + 448 = 5824
Step 14: 5824 + 448 = 6272
Step 15: 6272 + 448 = 6720
Step 16: 6720 + 448 = 7168
Step 17: 7168 + 448 = 7616
Step 18: 7616 + 448 = 8064
Step 19: 8064 + 448 = 8512
Step 20: 8512 + 448 = 8960
Step 21: 8960 + 448 = 9408

So, 448*21 = 9408