Let's roll up our sleeves and solve this. We have 402 and we're going to multiply it by 24, essentially adding 402 to itself 24 times.
Step 1: 0 + 402 = 402
Step 2: 402 + 402 = 804
Step 3: 804 + 402 = 1206
Step 4: 1206 + 402 = 1608
Step 5: 1608 + 402 = 2010
Step 6: 2010 + 402 = 2412
Step 7: 2412 + 402 = 2814
Step 8: 2814 + 402 = 3216
Step 9: 3216 + 402 = 3618
Step 10: 3618 + 402 = 4020
Step 11: 4020 + 402 = 4422
Step 12: 4422 + 402 = 4824
Step 13: 4824 + 402 = 5226
Step 14: 5226 + 402 = 5628
Step 15: 5628 + 402 = 6030
Step 16: 6030 + 402 = 6432
Step 17: 6432 + 402 = 6834
Step 18: 6834 + 402 = 7236
Step 19: 7236 + 402 = 7638
Step 20: 7638 + 402 = 8040
Step 21: 8040 + 402 = 8442
Step 22: 8442 + 402 = 8844
Step 23: 8844 + 402 = 9246
Step 24: 9246 + 402 = 9648

So, 402*24 = 9648