Alright, let's solve this math problem step by step. First, we have the number 140. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 60. So, we're going to take the number 140 and add it to itself 60 times.
Step 1: 0 + 140 = 140
Step 2: 140 + 140 = 280
Step 3: 280 + 140 = 420
Step 4: 420 + 140 = 560
Step 5: 560 + 140 = 700
Step 6: 700 + 140 = 840
Step 7: 840 + 140 = 980
Step 8: 980 + 140 = 1120
Step 9: 1120 + 140 = 1260
Step 10: 1260 + 140 = 1400
Step 11: 1400 + 140 = 1540
Step 12: 1540 + 140 = 1680
Step 13: 1680 + 140 = 1820
Step 14: 1820 + 140 = 1960
Step 15: 1960 + 140 = 2100
Step 16: 2100 + 140 = 2240
Step 17: 2240 + 140 = 2380
Step 18: 2380 + 140 = 2520
Step 19: 2520 + 140 = 2660
Step 20: 2660 + 140 = 2800
Step 21: 2800 + 140 = 2940
Step 22: 2940 + 140 = 3080
Step 23: 3080 + 140 = 3220
Step 24: 3220 + 140 = 3360
Step 25: 3360 + 140 = 3500
Step 26: 3500 + 140 = 3640
Step 27: 3640 + 140 = 3780
Step 28: 3780 + 140 = 3920
Step 29: 3920 + 140 = 4060
Step 30: 4060 + 140 = 4200
Step 31: 4200 + 140 = 4340
Step 32: 4340 + 140 = 4480
Step 33: 4480 + 140 = 4620
Step 34: 4620 + 140 = 4760
Step 35: 4760 + 140 = 4900
Step 36: 4900 + 140 = 5040
Step 37: 5040 + 140 = 5180
Step 38: 5180 + 140 = 5320
Step 39: 5320 + 140 = 5460
Step 40: 5460 + 140 = 5600
Step 41: 5600 + 140 = 5740
Step 42: 5740 + 140 = 5880
Step 43: 5880 + 140 = 6020
Step 44: 6020 + 140 = 6160
Step 45: 6160 + 140 = 6300
Step 46: 6300 + 140 = 6440
Step 47: 6440 + 140 = 6580
Step 48: 6580 + 140 = 6720
Step 49: 6720 + 140 = 6860
Step 50: 6860 + 140 = 7000
Step 51: 7000 + 140 = 7140
Step 52: 7140 + 140 = 7280
Step 53: 7280 + 140 = 7420
Step 54: 7420 + 140 = 7560
Step 55: 7560 + 140 = 7700
Step 56: 7700 + 140 = 7840
Step 57: 7840 + 140 = 7980
Step 58: 7980 + 140 = 8120
Step 59: 8120 + 140 = 8260
Step 60: 8260 + 140 = 8400

So, 140*60 = 8400