OBJECTIVE
To divide a thin strip of paper into a given number of equal parts (say into 8 equal parts)
extra fractions challenges for the early finishers.
Materials Required
A sheet of ruled paper in which all the lines are parallel and equidistant
Given rectangular strip of paper
A geometry box
PRACTICALITIES WHEN MAKING THE FRACTION WALL
Fractions with denominators as powers of 2 are easily made out of folding strips in half several times.
Consider the series 1 fold in 2 1 folding line 2 equal parts
2 folds in 2 3 folding lines 4 equal parts
3 folds in 2 7 folding lines 8 equal parts
All the other fractions are harder to make and here we use the method of grating or intercept method.
The same way as you grate cheese, that’s it, you can scar the cheese with lines separated at same intervals ; we will use a grid of evenly separated lines on an A4 paper, to position our strip so the corner of the strip is touching one line on the grid and tilt at an angle the strip so the length of the strip is being pierced by the lines on the grid.
Using memory aids to quickly identify and solve trigonometric problems.
It is a two step process involving two skills.
First skill:
IDENTIFY THE TRIGONOMETRIC
ANGLES, SIDES and HYPOTENUSE in different orientations
Second skill:
IDENTIFY the MNEMONIC that finds the VALUE sought and contains VALUES given
Important: if x is an angle value given it will appear in one of these ways as sin(x), cos(x) or tan(x) in the mnemonics.
2 MNEMONICS to find sides given an angle
Oriental Hoisin Sauce O= HSIN(t)
Apes Hug Cozily A= HCOS(t)
1 MNEMONIC to find the angle given two short sides and no hypotenuse
TorNAdos Over America t =TAN-1(O/A )
Tornados has NA inverted to remind you it is the inverse tangent