A Dictionary of Units [ Teens/Mature Teens ] - A summary of most of the units of measurement to be found in use around the world today (and a few of historical interest), together with the appropriate conversion factors needed to change them into a standard unit. http://www.ex.ac.uk/cimt/dictunit/dictunit.htm

Apples4theteacher.com [ Kids ] - Measure the teddy bears game. http://www.apples4theteacher.com/measure.html

Conversion Calculator [ Teens/Mature Teens ] - A simple calculator to convert between various units. http://www.thehaws.org/convert.shtml

Convert-me.Com [ Kids/Teens/Mature Teens ] - Interactive calculators for many common and exotic measurement systems, including metric, Ancient Greek, Roman, and old Russian. http://www.convert-me.com/en/

CyberSleuth: Units of Measurements Worksheets [ Kids ] - Twenty-three printable worksheets for elementary school-aged children. Focuses primarily on conversion of units of length. http://cybersleuth-kids.com/sleuth/Math/Math_Worksheets/Units_of_Measurement/

FAQ: How do I read a ruler? [ Kids/Teens ] - Instructions on how to use metric and English rulers. http://www.onlineconversion.com/faq_05.htm

Funbrain.com [ Kids/Teens ] - Measurement game - Game which has several levels of difficulty for both English and metric rulers. http://www.funbrain.com/measure/

GCSE Maths: Measurement [ Kids/Teens ] - Includes length, area and volume and the use of prefixes in units. With worked examples and animations. http://www.gcse.com/maths/measurement.htm

How Many? [ Teens/Mature Teens ] - A dictionary of units of measurement: explanations of the metric system, System Internationale (SI), English customary system, and other modern measuring systems. Plus extensive links to other measurement-related Internet resources. http://www.unc.edu/~rowlett/units/index.html

How To Read A Ruler [ Teens ] - Article describes all of those little lines and markings. http://www.woodzone.com/articles/Read_A_Ruler.htm

Jack's Math [ Teens/Mature Teens ] - Provides several methods for determining length, width and height. http://www.nps.gov/whmi/educate/ortrtg/11or1.htm

Measurement Worksheets [ Kids ] - Features printable worksheets. Includes English and Metric System pages. http://www.edhelper.com/measurement.htm

Measuring Angle and Distance with your Thumb [ Teens/Mature Teens ] - How to use body parts to estimate measurements. http://www.vendian.org/mncharity/dir3/bodyruler_angle/

Metric 4 US [ Teens/Mature Teens ] - A site promoting the metric system which argues why metric is better and English is worse. Provides an English-metric online calculator. http://www.metric4us.com/

Metric Conversion [ Teens ] - Java metric conversion calculator for length, weight, pressure, and volume. http://www.worldwidemetric.com/metcal.htm

Metric Conversion Tables [ Teens/Mature Teens ] - Conversion factors and online calculators for metric and imperial units. http://www.metric-conversion-tables.com/

Metric Conversion Tutorial [ Teens ] - Step-by-step, interactive tutorial for converting metric units. http://chemistry.boisestate.edu/rbanks/inorganic/metricconversion1.htm

Metric Measures [ Kids/Teens ] - Offers equivalents for common measurements, plus how metric units are used in sports and the kitchen. http://www.nist.gov/public_affairs/kids/metric.htm

Online Units Conversion [ Teens/Mature Teens ] - Gives equal values for areas, volumes, circle measurements, computer storage, currencies, distance and length, energy, fuel consumption, power, pressure, speed, temperature, time, torque, and weights. http://convertplus.com/en/

Origins of Measurements [ Kids/Teens ] - Compares units of ancient times with modern ones. http://www.iofm.net/community/kidscorner/maths/origin.htm