Alright, let's solve this math problem step by step. First, we have the number 680. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 251. So, we're going to take the number 680 and add it to itself 251 times.
Step 1: 0 + 680 = 680
Step 2: 680 + 680 = 1360
Step 3: 1360 + 680 = 2040
Step 4: 2040 + 680 = 2720
Step 5: 2720 + 680 = 3400
Step 6: 3400 + 680 = 4080
Step 7: 4080 + 680 = 4760
Step 8: 4760 + 680 = 5440
Step 9: 5440 + 680 = 6120
Step 10: 6120 + 680 = 6800
Step 11: 6800 + 680 = 7480
Step 12: 7480 + 680 = 8160
Step 13: 8160 + 680 = 8840
Step 14: 8840 + 680 = 9520
Step 15: 9520 + 680 = 10200
Step 16: 10200 + 680 = 10880
Step 17: 10880 + 680 = 11560
Step 18: 11560 + 680 = 12240
Step 19: 12240 + 680 = 12920
Step 20: 12920 + 680 = 13600
Step 21: 13600 + 680 = 14280
Step 22: 14280 + 680 = 14960
Step 23: 14960 + 680 = 15640
Step 24: 15640 + 680 = 16320
Step 25: 16320 + 680 = 17000
Step 26: 17000 + 680 = 17680
Step 27: 17680 + 680 = 18360
Step 28: 18360 + 680 = 19040
Step 29: 19040 + 680 = 19720
Step 30: 19720 + 680 = 20400
Step 31: 20400 + 680 = 21080
Step 32: 21080 + 680 = 21760
Step 33: 21760 + 680 = 22440
Step 34: 22440 + 680 = 23120
Step 35: 23120 + 680 = 23800
Step 36: 23800 + 680 = 24480
Step 37: 24480 + 680 = 25160
Step 38: 25160 + 680 = 25840
Step 39: 25840 + 680 = 26520
Step 40: 26520 + 680 = 27200
Step 41: 27200 + 680 = 27880
Step 42: 27880 + 680 = 28560
Step 43: 28560 + 680 = 29240
Step 44: 29240 + 680 = 29920
Step 45: 29920 + 680 = 30600
Step 46: 30600 + 680 = 31280
Step 47: 31280 + 680 = 31960
Step 48: 31960 + 680 = 32640
Step 49: 32640 + 680 = 33320
Step 50: 33320 + 680 = 34000
Step 51: 34000 + 680 = 34680
Step 52: 34680 + 680 = 35360
Step 53: 35360 + 680 = 36040
Step 54: 36040 + 680 = 36720
Step 55: 36720 + 680 = 37400
Step 56: 37400 + 680 = 38080
Step 57: 38080 + 680 = 38760
Step 58: 38760 + 680 = 39440
Step 59: 39440 + 680 = 40120
Step 60: 40120 + 680 = 40800
Step 61: 40800 + 680 = 41480
Step 62: 41480 + 680 = 42160
Step 63: 42160 + 680 = 42840
Step 64: 42840 + 680 = 43520
Step 65: 43520 + 680 = 44200
Step 66: 44200 + 680 = 44880
Step 67: 44880 + 680 = 45560
Step 68: 45560 + 680 = 46240
Step 69: 46240 + 680 = 46920
Step 70: 46920 + 680 = 47600
Step 71: 47600 + 680 = 48280
Step 72: 48280 + 680 = 48960
Step 73: 48960 + 680 = 49640
Step 74: 49640 + 680 = 50320
Step 75: 50320 + 680 = 51000
Step 76: 51000 + 680 = 51680
Step 77: 51680 + 680 = 52360
Step 78: 52360 + 680 = 53040
Step 79: 53040 + 680 = 53720
Step 80: 53720 + 680 = 54400
Step 81: 54400 + 680 = 55080
Step 82: 55080 + 680 = 55760
Step 83: 55760 + 680 = 56440
Step 84: 56440 + 680 = 57120
Step 85: 57120 + 680 = 57800
Step 86: 57800 + 680 = 58480
Step 87: 58480 + 680 = 59160
Step 88: 59160 + 680 = 59840
Step 89: 59840 + 680 = 60520
Step 90: 60520 + 680 = 61200
Step 91: 61200 + 680 = 61880
Step 92: 61880 + 680 = 62560
Step 93: 62560 + 680 = 63240
Step 94: 63240 + 680 = 63920
Step 95: 63920 + 680 = 64600
Step 96: 64600 + 680 = 65280
Step 97: 65280 + 680 = 65960
Step 98: 65960 + 680 = 66640
Step 99: 66640 + 680 = 67320
Step 100: 67320 + 680 = 68000
Step 101: 68000 + 680 = 68680
Step 102: 68680 + 680 = 69360
Step 103: 69360 + 680 = 70040
Step 104: 70040 + 680 = 70720
Step 105: 70720 + 680 = 71400
Step 106: 71400 + 680 = 72080
Step 107: 72080 + 680 = 72760
Step 108: 72760 + 680 = 73440
Step 109: 73440 + 680 = 74120
Step 110: 74120 + 680 = 74800
Step 111: 74800 + 680 = 75480
Step 112: 75480 + 680 = 76160
Step 113: 76160 + 680 = 76840
Step 114: 76840 + 680 = 77520
Step 115: 77520 + 680 = 78200
Step 116: 78200 + 680 = 78880
Step 117: 78880 + 680 = 79560
Step 118: 79560 + 680 = 80240
Step 119: 80240 + 680 = 80920
Step 120: 80920 + 680 = 81600
Step 121: 81600 + 680 = 82280
Step 122: 82280 + 680 = 82960
Step 123: 82960 + 680 = 83640
Step 124: 83640 + 680 = 84320
Step 125: 84320 + 680 = 85000
Step 126: 85000 + 680 = 85680
Step 127: 85680 + 680 = 86360
Step 128: 86360 + 680 = 87040
Step 129: 87040 + 680 = 87720
Step 130: 87720 + 680 = 88400
Step 131: 88400 + 680 = 89080
Step 132: 89080 + 680 = 89760
Step 133: 89760 + 680 = 90440
Step 134: 90440 + 680 = 91120
Step 135: 91120 + 680 = 91800
Step 136: 91800 + 680 = 92480
Step 137: 92480 + 680 = 93160
Step 138: 93160 + 680 = 93840
Step 139: 93840 + 680 = 94520
Step 140: 94520 + 680 = 95200
Step 141: 95200 + 680 = 95880
Step 142: 95880 + 680 = 96560
Step 143: 96560 + 680 = 97240
Step 144: 97240 + 680 = 97920
Step 145: 97920 + 680 = 98600
Step 146: 98600 + 680 = 99280
Step 147: 99280 + 680 = 99960
Step 148: 99960 + 680 = 100640
Step 149: 100640 + 680 = 101320
Step 150: 101320 + 680 = 102000
Step 151: 102000 + 680 = 102680
Step 152: 102680 + 680 = 103360
Step 153: 103360 + 680 = 104040
Step 154: 104040 + 680 = 104720
Step 155: 104720 + 680 = 105400
Step 156: 105400 + 680 = 106080
Step 157: 106080 + 680 = 106760
Step 158: 106760 + 680 = 107440
Step 159: 107440 + 680 = 108120
Step 160: 108120 + 680 = 108800
Step 161: 108800 + 680 = 109480
Step 162: 109480 + 680 = 110160
Step 163: 110160 + 680 = 110840
Step 164: 110840 + 680 = 111520
Step 165: 111520 + 680 = 112200
Step 166: 112200 + 680 = 112880
Step 167: 112880 + 680 = 113560
Step 168: 113560 + 680 = 114240
Step 169: 114240 + 680 = 114920
Step 170: 114920 + 680 = 115600
Step 171: 115600 + 680 = 116280
Step 172: 116280 + 680 = 116960
Step 173: 116960 + 680 = 117640
Step 174: 117640 + 680 = 118320
Step 175: 118320 + 680 = 119000
Step 176: 119000 + 680 = 119680
Step 177: 119680 + 680 = 120360
Step 178: 120360 + 680 = 121040
Step 179: 121040 + 680 = 121720
Step 180: 121720 + 680 = 122400
Step 181: 122400 + 680 = 123080
Step 182: 123080 + 680 = 123760
Step 183: 123760 + 680 = 124440
Step 184: 124440 + 680 = 125120
Step 185: 125120 + 680 = 125800
Step 186: 125800 + 680 = 126480
Step 187: 126480 + 680 = 127160
Step 188: 127160 + 680 = 127840
Step 189: 127840 + 680 = 128520
Step 190: 128520 + 680 = 129200
Step 191: 129200 + 680 = 129880
Step 192: 129880 + 680 = 130560
Step 193: 130560 + 680 = 131240
Step 194: 131240 + 680 = 131920
Step 195: 131920 + 680 = 132600
Step 196: 132600 + 680 = 133280
Step 197: 133280 + 680 = 133960
Step 198: 133960 + 680 = 134640
Step 199: 134640 + 680 = 135320
Step 200: 135320 + 680 = 136000
Step 201: 136000 + 680 = 136680
Step 202: 136680 + 680 = 137360
Step 203: 137360 + 680 = 138040
Step 204: 138040 + 680 = 138720
Step 205: 138720 + 680 = 139400
Step 206: 139400 + 680 = 140080
Step 207: 140080 + 680 = 140760
Step 208: 140760 + 680 = 141440
Step 209: 141440 + 680 = 142120
Step 210: 142120 + 680 = 142800
Step 211: 142800 + 680 = 143480
Step 212: 143480 + 680 = 144160
Step 213: 144160 + 680 = 144840
Step 214: 144840 + 680 = 145520
Step 215: 145520 + 680 = 146200
Step 216: 146200 + 680 = 146880
Step 217: 146880 + 680 = 147560
Step 218: 147560 + 680 = 148240
Step 219: 148240 + 680 = 148920
Step 220: 148920 + 680 = 149600
Step 221: 149600 + 680 = 150280
Step 222: 150280 + 680 = 150960
Step 223: 150960 + 680 = 151640
Step 224: 151640 + 680 = 152320
Step 225: 152320 + 680 = 153000
Step 226: 153000 + 680 = 153680
Step 227: 153680 + 680 = 154360
Step 228: 154360 + 680 = 155040
Step 229: 155040 + 680 = 155720
Step 230: 155720 + 680 = 156400
Step 231: 156400 + 680 = 157080
Step 232: 157080 + 680 = 157760
Step 233: 157760 + 680 = 158440
Step 234: 158440 + 680 = 159120
Step 235: 159120 + 680 = 159800
Step 236: 159800 + 680 = 160480
Step 237: 160480 + 680 = 161160
Step 238: 161160 + 680 = 161840
Step 239: 161840 + 680 = 162520
Step 240: 162520 + 680 = 163200
Step 241: 163200 + 680 = 163880
Step 242: 163880 + 680 = 164560
Step 243: 164560 + 680 = 165240
Step 244: 165240 + 680 = 165920
Step 245: 165920 + 680 = 166600
Step 246: 166600 + 680 = 167280
Step 247: 167280 + 680 = 167960
Step 248: 167960 + 680 = 168640
Step 249: 168640 + 680 = 169320
Step 250: 169320 + 680 = 170000
Step 251: 170000 + 680 = 170680

So, 680*251 = 170680