Alright, let's solve this math problem step by step. First, we have the number 306. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 70. So, we're going to take the number 306 and add it to itself 70 times.
Step 1: 0 + 306 = 306
Step 2: 306 + 306 = 612
Step 3: 612 + 306 = 918
Step 4: 918 + 306 = 1224
Step 5: 1224 + 306 = 1530
Step 6: 1530 + 306 = 1836
Step 7: 1836 + 306 = 2142
Step 8: 2142 + 306 = 2448
Step 9: 2448 + 306 = 2754
Step 10: 2754 + 306 = 3060
Step 11: 3060 + 306 = 3366
Step 12: 3366 + 306 = 3672
Step 13: 3672 + 306 = 3978
Step 14: 3978 + 306 = 4284
Step 15: 4284 + 306 = 4590
Step 16: 4590 + 306 = 4896
Step 17: 4896 + 306 = 5202
Step 18: 5202 + 306 = 5508
Step 19: 5508 + 306 = 5814
Step 20: 5814 + 306 = 6120
Step 21: 6120 + 306 = 6426
Step 22: 6426 + 306 = 6732
Step 23: 6732 + 306 = 7038
Step 24: 7038 + 306 = 7344
Step 25: 7344 + 306 = 7650
Step 26: 7650 + 306 = 7956
Step 27: 7956 + 306 = 8262
Step 28: 8262 + 306 = 8568
Step 29: 8568 + 306 = 8874
Step 30: 8874 + 306 = 9180
Step 31: 9180 + 306 = 9486
Step 32: 9486 + 306 = 9792
Step 33: 9792 + 306 = 10098
Step 34: 10098 + 306 = 10404
Step 35: 10404 + 306 = 10710
Step 36: 10710 + 306 = 11016
Step 37: 11016 + 306 = 11322
Step 38: 11322 + 306 = 11628
Step 39: 11628 + 306 = 11934
Step 40: 11934 + 306 = 12240
Step 41: 12240 + 306 = 12546
Step 42: 12546 + 306 = 12852
Step 43: 12852 + 306 = 13158
Step 44: 13158 + 306 = 13464
Step 45: 13464 + 306 = 13770
Step 46: 13770 + 306 = 14076
Step 47: 14076 + 306 = 14382
Step 48: 14382 + 306 = 14688
Step 49: 14688 + 306 = 14994
Step 50: 14994 + 306 = 15300
Step 51: 15300 + 306 = 15606
Step 52: 15606 + 306 = 15912
Step 53: 15912 + 306 = 16218
Step 54: 16218 + 306 = 16524
Step 55: 16524 + 306 = 16830
Step 56: 16830 + 306 = 17136
Step 57: 17136 + 306 = 17442
Step 58: 17442 + 306 = 17748
Step 59: 17748 + 306 = 18054
Step 60: 18054 + 306 = 18360
Step 61: 18360 + 306 = 18666
Step 62: 18666 + 306 = 18972
Step 63: 18972 + 306 = 19278
Step 64: 19278 + 306 = 19584
Step 65: 19584 + 306 = 19890
Step 66: 19890 + 306 = 20196
Step 67: 20196 + 306 = 20502
Step 68: 20502 + 306 = 20808
Step 69: 20808 + 306 = 21114
Step 70: 21114 + 306 = 21420

So, 306*70 = 21420