Let's get this math done. We have 690 and we're going to multiply it by 26. This is the same as taking 690 and adding it to itself 26 times.
Step 1: 0 + 690 = 690
Step 2: 690 + 690 = 1380
Step 3: 1380 + 690 = 2070
Step 4: 2070 + 690 = 2760
Step 5: 2760 + 690 = 3450
Step 6: 3450 + 690 = 4140
Step 7: 4140 + 690 = 4830
Step 8: 4830 + 690 = 5520
Step 9: 5520 + 690 = 6210
Step 10: 6210 + 690 = 6900
Step 11: 6900 + 690 = 7590
Step 12: 7590 + 690 = 8280
Step 13: 8280 + 690 = 8970
Step 14: 8970 + 690 = 9660
Step 15: 9660 + 690 = 10350
Step 16: 10350 + 690 = 11040
Step 17: 11040 + 690 = 11730
Step 18: 11730 + 690 = 12420
Step 19: 12420 + 690 = 13110
Step 20: 13110 + 690 = 13800
Step 21: 13800 + 690 = 14490
Step 22: 14490 + 690 = 15180
Step 23: 15180 + 690 = 15870
Step 24: 15870 + 690 = 16560
Step 25: 16560 + 690 = 17250
Step 26: 17250 + 690 = 17940

So, 690*26 = 17940