Let's roll up our sleeves and solve this. We have 257 and we're going to multiply it by 7, essentially adding 257 to itself 7 times.
Step 1: 0 + 257 = 257
Step 2: 257 + 257 = 514
Step 3: 514 + 257 = 771
Step 4: 771 + 257 = 1028
Step 5: 1028 + 257 = 1285
Step 6: 1285 + 257 = 1542
Step 7: 1542 + 257 = 1799

So, 257*7 = 1799