Lego Tower Math Enrichment

The Lego Challenge
The original problem was find out how much money the whole tower costed to build. We had 3 sets of legos to find out the answer: 

Set A: has 405 pieces  and the cost is: $28.99. 
Set B: has 650 pieces and the cost is: $26.95. 
Set C: has 704 pieces and the cost is: $44.97. 

The cost of making the lego tower is $35,802.65 if you were using set A. The cost would be $20,751.50 if you were using set B. The cost would be $35,973.67 if you were using set C. The first thing I did is estimate the cost and amount of sets needed for each of the sets. A: about 1,300 sets needed. About $39,000 spent. B: about 700 sets. About $31,500 spent. C: about 800 sets needed. About $21,600 spent. I used a spreadsheet to help us multiply and divide because the multiplication and division needed to answer the problem is too challenging and confusing for 4th graders. The problem was that the spreadsheet had decimals so we had to round up because you can not buy part of a set. Next, I put all my data listed on the spreadsheet into the interactive chart above for everyone who is viewing my blog to see.
By Emma