In Sheet1, in the B1 cell, enter this formula after adjusting however many rows you have on Sheet2.
Code:
=VLOOKUP(A1,Sheet2!$A$1:$B$11,2,FALSE)
Then, fill that formula down in Sheet1's B column to however many rows you have in Sheet1.
Here's my Sheet1
[TABLE="width: 128"]
<colgroup><col style="width:48pt" width="64" span="2"> </colgroup><tbody>[TR]
[TD="class: xl63, width: 64, align: right"]4[/TD]
[TD="class: xl63, width: 64, align: right"]800[/TD]
[/TR]
[TR]
[TD="class: xl63, align: right"]22170255[/TD]
[TD="class: xl63, align: right"]1000[/TD]
[/TR]
[TR]
[TD="class: xl63, align: right"]9[/TD]
[TD="class: xl63, align: right"]1300[/TD]
[/TR]
[TR]
[TD="class: xl63, align: right"]1[/TD]
[TD="class: xl63, align: right"]500[/TD]
[/TR]
[TR]
[TD="class: xl63, align: right"]10[/TD]
[TD="class: xl63, align: right"]15000[/TD]
[/TR]
[TR]
[TD="class: xl63, align: right"]7[/TD]
[TD="class: xl63, align: right"]1100[/TD]
[/TR]
[TR]
[TD="class: xl63, align: right"]9[/TD]
[TD="class: xl63, align: right"]1300[/TD]
[/TR]
[TR]
[TD="class: xl63, align: right"]8[/TD]
[TD="class: xl63, align: right"]1200[/TD]
[/TR]
[TR]
[TD="class: xl63, align: right"]6[/TD]
[TD="class: xl63, align: right"]1400[/TD]
[/TR]
[TR]
[TD="class: xl63, align: right"]7[/TD]
[TD="class: xl63, align: right"]1100[/TD]
[/TR]
</tbody>[/TABLE]
And, here's my Sheet2
[TABLE="width: 128"]
<colgroup><col style="width:48pt" width="64" span="2"> </colgroup><tbody>[TR]
[TD="class: xl65, width: 64, align: right"]1[/TD]
[TD="class: xl65, width: 64, align: right"]500[/TD]
[/TR]
[TR]
[TD="class: xl65, align: right"]2[/TD]
[TD="class: xl65, align: right"]600[/TD]
[/TR]
[TR]
[TD="class: xl65, align: right"]3[/TD]
[TD="class: xl65, align: right"]700[/TD]
[/TR]
[TR]
[TD="class: xl65, align: right"]4[/TD]
[TD="class: xl65, align: right"]800[/TD]
[/TR]
[TR]
[TD="class: xl65, align: right"]5[/TD]
[TD="class: xl65, align: right"]900[/TD]
[/TR]
[TR]
[TD="class: xl65, align: right"]22170255[/TD]
[TD="class: xl65, align: right"]1000[/TD]
[/TR]
[TR]
[TD="class: xl65, align: right"]7[/TD]
[TD="class: xl65, align: right"]1100[/TD]
[/TR]
[TR]
[TD="class: xl65, align: right"]8[/TD]
[TD="class: xl65, align: right"]1200[/TD]
[/TR]
[TR]
[TD="class: xl65, align: right"]9[/TD]
[TD="class: xl65, align: right"]1300[/TD]
[/TR]
[TR]
[TD="class: xl65, align: right"]6[/TD]
[TD="class: xl65, align: right"]1400[/TD]
[/TR]
[TR]
[TD="class: xl65, align: right"]10[/TD]
[TD="class: xl65, align: right"]15000[/TD]
[/TR]
</tbody>[/TABLE]