Let's get this math done. We have 12 and we're going to multiply it by 25. This is the same as taking 12 and adding it to itself 25 times.
Step 1: 0 + 12 = 12
Step 2: 12 + 12 = 24
Step 3: 24 + 12 = 36
Step 4: 36 + 12 = 48
Step 5: 48 + 12 = 60
Step 6: 60 + 12 = 72
Step 7: 72 + 12 = 84
Step 8: 84 + 12 = 96
Step 9: 96 + 12 = 108
Step 10: 108 + 12 = 120
Step 11: 120 + 12 = 132
Step 12: 132 + 12 = 144
Step 13: 144 + 12 = 156
Step 14: 156 + 12 = 168
Step 15: 168 + 12 = 180
Step 16: 180 + 12 = 192
Step 17: 192 + 12 = 204
Step 18: 204 + 12 = 216
Step 19: 216 + 12 = 228
Step 20: 228 + 12 = 240
Step 21: 240 + 12 = 252
Step 22: 252 + 12 = 264
Step 23: 264 + 12 = 276
Step 24: 276 + 12 = 288
Step 25: 288 + 12 = 300

So, 12*25 = 300