OK, let's work through this together. We're starting with 783 and we're going to multiply it by 7, which means we add 783 to itself 7 times.
Step 1: 0 + 783 = 783
Step 2: 783 + 783 = 1566
Step 3: 1566 + 783 = 2349
Step 4: 2349 + 783 = 3132
Step 5: 3132 + 783 = 3915
Step 6: 3915 + 783 = 4698
Step 7: 4698 + 783 = 5481

So, 783*7 = 5481