OK, let's crack this. We're given 900 and our task is to multiply it by 26. Essentially, we'll be adding 900 to itself 26 times.
Step 1: 0 + 900 = 900
Step 2: 900 + 900 = 1800
Step 3: 1800 + 900 = 2700
Step 4: 2700 + 900 = 3600
Step 5: 3600 + 900 = 4500
Step 6: 4500 + 900 = 5400
Step 7: 5400 + 900 = 6300
Step 8: 6300 + 900 = 7200
Step 9: 7200 + 900 = 8100
Step 10: 8100 + 900 = 9000
Step 11: 9000 + 900 = 9900
Step 12: 9900 + 900 = 10800
Step 13: 10800 + 900 = 11700
Step 14: 11700 + 900 = 12600
Step 15: 12600 + 900 = 13500
Step 16: 13500 + 900 = 14400
Step 17: 14400 + 900 = 15300
Step 18: 15300 + 900 = 16200
Step 19: 16200 + 900 = 17100
Step 20: 17100 + 900 = 18000
Step 21: 18000 + 900 = 18900
Step 22: 18900 + 900 = 19800
Step 23: 19800 + 900 = 20700
Step 24: 20700 + 900 = 21600
Step 25: 21600 + 900 = 22500
Step 26: 22500 + 900 = 23400

So, 900*26 = 23400