OK, let's work through this together. We're starting with 745 and we're going to multiply it by 20, which means we add 745 to itself 20 times.
Step 1: 0 + 745 = 745
Step 2: 745 + 745 = 1490
Step 3: 1490 + 745 = 2235
Step 4: 2235 + 745 = 2980
Step 5: 2980 + 745 = 3725
Step 6: 3725 + 745 = 4470
Step 7: 4470 + 745 = 5215
Step 8: 5215 + 745 = 5960
Step 9: 5960 + 745 = 6705
Step 10: 6705 + 745 = 7450
Step 11: 7450 + 745 = 8195
Step 12: 8195 + 745 = 8940
Step 13: 8940 + 745 = 9685
Step 14: 9685 + 745 = 10430
Step 15: 10430 + 745 = 11175
Step 16: 11175 + 745 = 11920
Step 17: 11920 + 745 = 12665
Step 18: 12665 + 745 = 13410
Step 19: 13410 + 745 = 14155
Step 20: 14155 + 745 = 14900

So, 745*20 = 14900