Math Leadership Support Network 08-09 Developing Formulas for Perimeter and Area.

Presentation on theme: "Math Leadership Support Network 08-09 Developing Formulas for Perimeter and Area."— Presentation transcript:

Math Leadership Support Network 08-09 Developing Formulas for Perimeter and Area

Math Leadership Support Network 08-09 With your talking partner(s), discuss… Why do our students struggle with finding Perimeter and Area?

Math Leadership Support Network 08-09 Prancer the Perimeter Pony

Math Leadership Support Network 08-09 x

Arnie, the Area Aardvark

Classroom Practice: 1. How many steps will it take for Prancer to prance around the Prancer to prance around the perimeter of…. perimeter of…. - an index card? - your binder? - your desk? - the poster on the wall?

Math Leadership Support Network 08-09 Classroom Practice: 1. How many Arnies will it take to cover… - an index card? - your binder? - your desk? - the poster on the wall?

Math Leadership Support Network 08-09 Use your 5 one inch square tiles to create one field for Arnie and Prancer. * Sides must be connected, not just vertices… NOT

Math Leadership Support Network 08-09 Compare your field to the fields of your table partners… Did we all get the same field? If we prance Prancer around our fields, would we all get the same perimeter?

Math Leadership Support Network 08-09 We all used 5 square tiles… Did we get the same perimeter with Prancer? Did we get the same area with Arnie? How can this happen?

Math Leadership Support Network 08-09 Continue to use 5 square tiles, but this time record your fields on the geo paper and FIND AS MANY FIELDS AS YOU CAN…

Math Leadership Support Network 08-09 What are we building with the 5 squares? WHY are we using 5 square tiles and not 4? Why are we going from using tiles to geo-board paper?

Math Leadership Support Network 08-09 How many different fields did you come up with?

Math Leadership Support Network 08-09 Try different sizes of fields with your partner…. (see fields 1-11)

Math Leadership Support Network 08-09 Dig Deeper… What if I have 24 feet of fencing? Will the same 24 feet, regardless of how I lay it out, yield the same pen? What if I have 24 feet of fencing? Will the same 24 feet, regardless of how I lay it out, yield the same pen?

Math Leadership Support Network 08-09 Dig Deeper… If I know that I have an AREA of 8 square units, can you draw me a shape?

Math Leadership Support Network 08-09 Dig Deeper… If I know that I have a perimenter of 8 units, can you draw me a shape?

Math Leadership Support Network 08-09 When we just give our students a formula up front, we give them permission to quit thinking…. Additionally, we assume that students can identify base and height and plug-and-chug those values into a formula….

Math Leadership Support Network 08-09 What is the formula that we give our students for finding the area of rectangles?