Surprise Party is a math project you can use later in the year for third graders and throughout the year as review for fourth graders. Among the skills reviewed are:
Story Problems (it’s one gigantic story problem!)
Division (without leftovers)
Adding Decimals (Money)
Measurement (inches and centimeters)
Also, students revisit writing dates and addresses, and there is an optional page that gives students reason to practice handwriting!
The answer key shows some of the ways my own students have solved these problems, but there are certainly other ways to arrive at the answers.