Alright, let's solve this math problem step by step. First, we have the number 853. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 40. So, we're going to take the number 853 and add it to itself 40 times.
Step 1: 0 + 853 = 853
Step 2: 853 + 853 = 1706
Step 3: 1706 + 853 = 2559
Step 4: 2559 + 853 = 3412
Step 5: 3412 + 853 = 4265
Step 6: 4265 + 853 = 5118
Step 7: 5118 + 853 = 5971
Step 8: 5971 + 853 = 6824
Step 9: 6824 + 853 = 7677
Step 10: 7677 + 853 = 8530
Step 11: 8530 + 853 = 9383
Step 12: 9383 + 853 = 10236
Step 13: 10236 + 853 = 11089
Step 14: 11089 + 853 = 11942
Step 15: 11942 + 853 = 12795
Step 16: 12795 + 853 = 13648
Step 17: 13648 + 853 = 14501
Step 18: 14501 + 853 = 15354
Step 19: 15354 + 853 = 16207
Step 20: 16207 + 853 = 17060
Step 21: 17060 + 853 = 17913
Step 22: 17913 + 853 = 18766
Step 23: 18766 + 853 = 19619
Step 24: 19619 + 853 = 20472
Step 25: 20472 + 853 = 21325
Step 26: 21325 + 853 = 22178
Step 27: 22178 + 853 = 23031
Step 28: 23031 + 853 = 23884
Step 29: 23884 + 853 = 24737
Step 30: 24737 + 853 = 25590
Step 31: 25590 + 853 = 26443
Step 32: 26443 + 853 = 27296
Step 33: 27296 + 853 = 28149
Step 34: 28149 + 853 = 29002
Step 35: 29002 + 853 = 29855
Step 36: 29855 + 853 = 30708
Step 37: 30708 + 853 = 31561
Step 38: 31561 + 853 = 32414
Step 39: 32414 + 853 = 33267
Step 40: 33267 + 853 = 34120

So, 853*40 = 34120