Alright, let's solve this math problem step by step. First, we have the number 780. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 24. So, we're going to take the number 780 and add it to itself 24 times.
Step 1: 0 + 780 = 780
Step 2: 780 + 780 = 1560
Step 3: 1560 + 780 = 2340
Step 4: 2340 + 780 = 3120
Step 5: 3120 + 780 = 3900
Step 6: 3900 + 780 = 4680
Step 7: 4680 + 780 = 5460
Step 8: 5460 + 780 = 6240
Step 9: 6240 + 780 = 7020
Step 10: 7020 + 780 = 7800
Step 11: 7800 + 780 = 8580
Step 12: 8580 + 780 = 9360
Step 13: 9360 + 780 = 10140
Step 14: 10140 + 780 = 10920
Step 15: 10920 + 780 = 11700
Step 16: 11700 + 780 = 12480
Step 17: 12480 + 780 = 13260
Step 18: 13260 + 780 = 14040
Step 19: 14040 + 780 = 14820
Step 20: 14820 + 780 = 15600
Step 21: 15600 + 780 = 16380
Step 22: 16380 + 780 = 17160
Step 23: 17160 + 780 = 17940
Step 24: 17940 + 780 = 18720

So, 780*24 = 18720