Alright, let's solve this math problem step by step. First, we have the number 615. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 26. So, we're going to take the number 615 and add it to itself 26 times.
Step 1: 0 + 615 = 615
Step 2: 615 + 615 = 1230
Step 3: 1230 + 615 = 1845
Step 4: 1845 + 615 = 2460
Step 5: 2460 + 615 = 3075
Step 6: 3075 + 615 = 3690
Step 7: 3690 + 615 = 4305
Step 8: 4305 + 615 = 4920
Step 9: 4920 + 615 = 5535
Step 10: 5535 + 615 = 6150
Step 11: 6150 + 615 = 6765
Step 12: 6765 + 615 = 7380
Step 13: 7380 + 615 = 7995
Step 14: 7995 + 615 = 8610
Step 15: 8610 + 615 = 9225
Step 16: 9225 + 615 = 9840
Step 17: 9840 + 615 = 10455
Step 18: 10455 + 615 = 11070
Step 19: 11070 + 615 = 11685
Step 20: 11685 + 615 = 12300
Step 21: 12300 + 615 = 12915
Step 22: 12915 + 615 = 13530
Step 23: 13530 + 615 = 14145
Step 24: 14145 + 615 = 14760
Step 25: 14760 + 615 = 15375
Step 26: 15375 + 615 = 15990

So, 615*26 = 15990