Let's roll up our sleeves and solve this. We have 790 and we're going to multiply it by 10, essentially adding 790 to itself 10 times.
Step 1: 0 + 790 = 790
Step 2: 790 + 790 = 1580
Step 3: 1580 + 790 = 2370
Step 4: 2370 + 790 = 3160
Step 5: 3160 + 790 = 3950
Step 6: 3950 + 790 = 4740
Step 7: 4740 + 790 = 5530
Step 8: 5530 + 790 = 6320
Step 9: 6320 + 790 = 7110
Step 10: 7110 + 790 = 7900

So, 790*10 = 7900