Let's roll up our sleeves and solve this. We have 20 and we're going to multiply it by 35, essentially adding 20 to itself 35 times.
Step 1: 0 + 20 = 20
Step 2: 20 + 20 = 40
Step 3: 40 + 20 = 60
Step 4: 60 + 20 = 80
Step 5: 80 + 20 = 100
Step 6: 100 + 20 = 120
Step 7: 120 + 20 = 140
Step 8: 140 + 20 = 160
Step 9: 160 + 20 = 180
Step 10: 180 + 20 = 200
Step 11: 200 + 20 = 220
Step 12: 220 + 20 = 240
Step 13: 240 + 20 = 260
Step 14: 260 + 20 = 280
Step 15: 280 + 20 = 300
Step 16: 300 + 20 = 320
Step 17: 320 + 20 = 340
Step 18: 340 + 20 = 360
Step 19: 360 + 20 = 380
Step 20: 380 + 20 = 400
Step 21: 400 + 20 = 420
Step 22: 420 + 20 = 440
Step 23: 440 + 20 = 460
Step 24: 460 + 20 = 480
Step 25: 480 + 20 = 500
Step 26: 500 + 20 = 520
Step 27: 520 + 20 = 540
Step 28: 540 + 20 = 560
Step 29: 560 + 20 = 580
Step 30: 580 + 20 = 600
Step 31: 600 + 20 = 620
Step 32: 620 + 20 = 640
Step 33: 640 + 20 = 660
Step 34: 660 + 20 = 680
Step 35: 680 + 20 = 700

So, 20*35 = 700