CARLETON — When she grows up, an Eyler Elementary School student said she now knows how to build a sandbox for her future children. Third-grader Emmerson McMahan recently mastered crunching the numbers needed to complete home improvement projects, thanks to a recent classroom activity that prompted t\he young Jets to don hard hats and neon vests. Third-graders mimicked construction workers and their classroom was transformed into a job site Thursday as groups applied concepts of area and perimeter to assess shapes and sizes for hypothetical school sandboxes and an art mural, accordin...