Students join the midpoints of the sides of a 2 x 2 square on a geoboard to form a smaller square. They determine the area of the smaller square and explore the lengths of its four sides. Develop, apply, and explain procedures for computation and estimation with whole numbers, fractions, decimals, integers, and rational numbers. Students develop rules for integer operations by using postman stories , as described in Robert Davis' Discovery in Mathematics . The teacher plays the role of a postman who delivers mail to the students.
Students model subtraction with two-color chips by adding pairs of red and yellow chips.
Develop, apply, and explain methods for solving problems involving proportions and percents. They list the measures in a table and discuss observations and possible relationships. After the estimate is made, pi is used to solve a variety of real-world circle problems. Students use holiday circulars advertising big sales on games and toys to comparison shop for specific items between different stores. One morning, as the students arrive at school, they see a giant handprint left on the blackboard overnight.