Let's get this math done. We have 25 and we're going to multiply it by 42. This is the same as taking 25 and adding it to itself 42 times.
Step 1: 0 + 25 = 25
Step 2: 25 + 25 = 50
Step 3: 50 + 25 = 75
Step 4: 75 + 25 = 100
Step 5: 100 + 25 = 125
Step 6: 125 + 25 = 150
Step 7: 150 + 25 = 175
Step 8: 175 + 25 = 200
Step 9: 200 + 25 = 225
Step 10: 225 + 25 = 250
Step 11: 250 + 25 = 275
Step 12: 275 + 25 = 300
Step 13: 300 + 25 = 325
Step 14: 325 + 25 = 350
Step 15: 350 + 25 = 375
Step 16: 375 + 25 = 400
Step 17: 400 + 25 = 425
Step 18: 425 + 25 = 450
Step 19: 450 + 25 = 475
Step 20: 475 + 25 = 500
Step 21: 500 + 25 = 525
Step 22: 525 + 25 = 550
Step 23: 550 + 25 = 575
Step 24: 575 + 25 = 600
Step 25: 600 + 25 = 625
Step 26: 625 + 25 = 650
Step 27: 650 + 25 = 675
Step 28: 675 + 25 = 700
Step 29: 700 + 25 = 725
Step 30: 725 + 25 = 750
Step 31: 750 + 25 = 775
Step 32: 775 + 25 = 800
Step 33: 800 + 25 = 825
Step 34: 825 + 25 = 850
Step 35: 850 + 25 = 875
Step 36: 875 + 25 = 900
Step 37: 900 + 25 = 925
Step 38: 925 + 25 = 950
Step 39: 950 + 25 = 975
Step 40: 975 + 25 = 1000
Step 41: 1000 + 25 = 1025
Step 42: 1025 + 25 = 1050

So, 25*42 = 1050