By correcting the homework of my third on the geometry in space, I realized they did not figure, they imagined any section by a plane making practical calculations.
calculations were correct but difficult to read without the figure.
To force them to ask these questions, I proposed a practical session.
I arranged the tables different everyday objects.
The orders were to calculate the internal volume.
They had at their disposal rules, compasses, calipers and if they asked, bits of string. The work was expected
conducting a poster presenting their approach.
Lacking figure drawn in the statement, they were obliged to make a name for the points.
That day, my classroom was a bit like a trade fair at all.
The junction box for electrical outlets.
Two hemispheres + cylinder
Besides the use of calipers, no problem.
The roll of Scotch double-sided
difference of two cylinders
Using calipers.
No difficulties, but to show that the volumes do not always add.
jar of jam.
a right prism + 1 cylinder
The main difficulty was to calculate the area of the base, which is a hexagon.
Using calipers.
lampshades and funnels
truncated cone and truncated pyramid.
The calculation is more complicated and more ambitious. Indeed, we must find the position of the truncated apex.
Using the Pythagorean theorem, the theorem of Thales.
resolution of an equation.
Some students used several methods to locate the approximate position of the top: using multiple rules, pieces of string (it had to be cut to length, because impossible to remove with your finger on the right mark.)
Some students came to a very fine resolution of the problem of lampshades, others were content to make an approximation.
Anyway, they all made plans.
0 comments:
Post a Comment