Alright, let's solve this math problem step by step. First, we have the number 160. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 21. So, we're going to take the number 160 and add it to itself 21 times.
Step 1: 0 + 160 = 160
Step 2: 160 + 160 = 320
Step 3: 320 + 160 = 480
Step 4: 480 + 160 = 640
Step 5: 640 + 160 = 800
Step 6: 800 + 160 = 960
Step 7: 960 + 160 = 1120
Step 8: 1120 + 160 = 1280
Step 9: 1280 + 160 = 1440
Step 10: 1440 + 160 = 1600
Step 11: 1600 + 160 = 1760
Step 12: 1760 + 160 = 1920
Step 13: 1920 + 160 = 2080
Step 14: 2080 + 160 = 2240
Step 15: 2240 + 160 = 2400
Step 16: 2400 + 160 = 2560
Step 17: 2560 + 160 = 2720
Step 18: 2720 + 160 = 2880
Step 19: 2880 + 160 = 3040
Step 20: 3040 + 160 = 3200
Step 21: 3200 + 160 = 3360

So, 160*21 = 3360