what are the activities for 'stretching' in mathematics?

Question

what i meant of stretching here was in the sense of mathematical enlargement. the activities are for ages 11 above

Answer 1

Are you using stretching in the sense of mathematical enlargement? Or is it in the sense of activities to stretch the minds of more able students? I have plenty of the latter from my many years of teaching experience. However, I'm not going to put them here until I know that is what you mean. Also I would need to know what ages they are for. Mine are all for about age 11 upwards although some might do for a year or two younger. Also an idea of ability would be useful.

Edit. The obvious example is photographic enlargements or reductions. Another might be the picture on a balloon as it is blown up although here you have the difficulty of a spherical surface. Different scale maps of the same area is another. A three dimensional application is models made to different scales.

Answer 2

If you're a math teacher, "stretching" activities would be activities to get kids thinking of math concepts in different ways. Since most kids are still operating at the concrete level, good stretching activities would be activities that get them to notice and/or apply math concepts to everyday life situations.
Most people relate to money. So use money, and make it concrete. For example, take a grocery bill, figure the percent spent on grains, meats, treats, etc. Figure the cost per unit weight. This would teach percentages and ratios as a stretching activity.