How do I tell / show my daughter how to find the perimeter of something ? (she is in the 5th grade.

If a circle, Pi X 2 X radius(distance from center of circle to outer edge of circle).
If Square, rectangle, or other shape, then it is the total of all sides. Good Luck
Area and Perimeter of a Circle (http://math.about.com/od/formulas/ss/areaperimeter_5.htm)

First take some common objects and use a piece of string and wrap it around it.

Pick some common objects around the house. A box; use different orientations, a square, a dish and later some odd shaped things.

Have her cut out pieces of string for each side so she can get the idea of 4a and 2*a + 2*b. Draw a circle using the string and tack method. Put string around the outside. Cut it to length. Measure the string. Compare against PI*D.

Come up with some examples. We want to put edging around a tree. Go outside, pick a tree. Ask where it would look good.

Let here try to figure out how to do some of it. Use something like a tomatoe plant aand then something with a trunk of about 5" and then something that's difficult to measure like a 20" trunk. Go from wrapping a string, getting perimeter, finding diameter. Pick a spot where the edging will look good and have her try to figure out how much she would need.

This abstact thinking stuff is nuts. Use the stuff for something practical.

Don't give the answer. Cause her to think for herself by asking questions.

What happens is that school seems to teach what to think. Not how to think and/or apply knowledge.