Let's get this math done. We have 23 and we're going to multiply it by 13. This is the same as taking 23 and adding it to itself 13 times.
Step 1: 0 + 23 = 23
Step 2: 23 + 23 = 46
Step 3: 46 + 23 = 69
Step 4: 69 + 23 = 92
Step 5: 92 + 23 = 115
Step 6: 115 + 23 = 138
Step 7: 138 + 23 = 161
Step 8: 161 + 23 = 184
Step 9: 184 + 23 = 207
Step 10: 207 + 23 = 230
Step 11: 230 + 23 = 253
Step 12: 253 + 23 = 276
Step 13: 276 + 23 = 299

So, 23*13 = 299