Measuring the radius and circumference of circles:
"We measured the radius using a ruler and and circumference of circles using a piece of string. We compared the size of the radius and circumference of all the circles and found that the circumference was always a bit more than three times the diameter of the circle. We found out that this is the number pi."
Dr. Maths answers the question "What is pi?" http://mathforum.org/dr.math/faq/faq.pi.html
Pi at Wikipedia - http://en.wikipedia.org/wiki/Pi
More about pi at "Maths is Fun!" - http://www.mathsisfun.com/numbers/pi.html
Read about how Archimedes (the famous Greek mathematician) discovered pi - http://www.sciencetrek.net/archimedes.htm

IntroductionGlossary of ancient weights and measures - http://www.hemyockcastle.co.uk/measure.htm

On-line distance and length converter - http://www.convert-me.com/en/convert/length

Ancient Roman units of length - http://en.wikipedia.org/wiki/Ancient_Roman_units_of_measurement

Ancient Egyptian units of measurement - http://en.wikipedia.org/wiki/Ancient_Egyptian_units_of_measurement

Ancient Egyptian cubit divided into fingers, palms and hands. - http://www.mathorigins.com/image%20grid/CUBIT_003.htm

What units do I use? http://www.bgfl.org/bgfl/custom/resources_ftp/client_ftp/ks2/maths/measures/index.htm

BBC Measurement Activities - http://www.bbc.co.uk/schools/ks3bitesize/maths/measures/

Measuring Length and Perimeter"Where is my peanut?" - http://www.eduref.org/Virtual/Lessons/Science/Process_Skills/SPS0011.html

Extension activities for peanuts - http://www.ciblearning.org/resource.exercise.measurement.php

Can shapes have the same area but different perimeters? A video from Math Playground - http://www.mathplayground.com/howto_sameareadiffperimeter.html

HOT maths area and perimeter - http://www.hotmaths.com.au/FreeActivities/flashPopup.jsp?stage=undefined&flashFile=/upload/CS_1/T_49/C_93/TUTORIAL/7_49_93_CompareAreaPerimeter_W02.swf

What units would you use?Measuring AreaAssessment task for Area, perimeter, scale and ratio - Creating a House plan.

Measure length, area and perimeter - http://www.woodlands-junior.kent.sch.uk/maths/measures/measure.html#Measure

Vpod song - http://vodpod.com/watch/979790-perimeter-and-area

Measuring area - Fence it! http://nrich.maths.org/public/viewer.php?obj_id=2663&part

Maths Playground interactive activity about area and perimeter - http://www.mathplayground.com/area_perimeter.html

Measuring AnglesCalculating angles - an interactive learning object http://nationalstrategies.standards.dcsf.gov.uk/node/47767

Measuring MassLearning object from UK (Measuring scales) - http://nationalstrategies.standards.dcsf.gov.uk/node/47789?uc=force_uj

Measuring the radius and circumference of circles:"We measured the radius using a ruler and and circumference of circles using a piece of string. We compared the size of the radius and circumference of all the circles and found that the circumference was always a bit more than three times the diameter of the circle. We found out that this is the number pi."

Dr. Maths answers the question "What is pi?" http://mathforum.org/dr.math/faq/faq.pi.html

Pi at Wikipedia - http://en.wikipedia.org/wiki/Pi

More about pi at "Maths is Fun!" - http://www.mathsisfun.com/numbers/pi.html

Read about how Archimedes (the famous Greek mathematician) discovered pi - http://www.sciencetrek.net/archimedes.htm

## The Adventures of Martin the Meter Ruler