The student will demonstrate through the mathematical processes an understanding of length, time, weight, and liquid volume measurements; the relationships between systems of measure; accurate, efficient, and generalizable methods of determining the perimeters of polygons; and the values and combinations of coins required to make change.

Lesson: Introduces students to modular (clock) arithmetic and how modular arithmetic can be used to encode messages using simple shift, multiple and affine ciphers.

Lesson: Students learn about perimeter and the units used to measure perimeter using a variety of materials including their hands, feet, rulers, and computer applets.

Activity: Practice reading a clock, input times for the clock to display, or let the clock generate random times for you to read. Choose from three difficulty levels. Clock Wise is one of the Interactivate assessment explorers.

Activity: Compare two sets of objects, using estimation to determine which is greater. Estimate a number of objects, the length of a line, or the area of a shape. Parameter: error tolerance. Comparison Estimator is one of the Interactivate assessment explorers.

Activity: Practice estimation skills by determining the number of objects, the length of a line, or the area of a shape. Parameters: error tolerance of estimate. Estimator is one of the Interactivate assessment explorers.

Activity: Practice estimation skills by determining whether the number of objects, the length of a line, or the area of a shape is more or less than the number given. Parameters: error tolerance of estimate. More or Less Estimator is one of the Interactivate assessment explorers.