Sure thing! We've got 870 and we're gonna multiply it by 9. That's the same as adding 870 to itself 9 times.
Step 1: 0 + 870 = 870
Step 2: 870 + 870 = 1740
Step 3: 1740 + 870 = 2610
Step 4: 2610 + 870 = 3480
Step 5: 3480 + 870 = 4350
Step 6: 4350 + 870 = 5220
Step 7: 5220 + 870 = 6090
Step 8: 6090 + 870 = 6960
Step 9: 6960 + 870 = 7830

So, 870*9 = 7830