This animation works through numbers, showing by pattern arrangements, how non-prime numbers can be factorised, but prime numbers cannot.
The author of Bad Science, a book which debunks lots of pseudoscience, presents a paper supporting the idea of Education Policy being driven by methods that have been scientifically demonstrated to work well, rather than the hit-and-miss political approach we currently ‘enjoy’:
The idea of using evidence-based policy is presented rather convincingly in The Geek Manifesto.
“In secondary school, however, parental engagement can often drop away altogether. Sometimes it’s because teenagers simply don’t want to engage with their parents on anything. Just as often, though, it’s because parents don’t feel empowered to help. They don’t recognise the maths their teenager is doing (or if they do, they can’t remember how to do it) and in many cases they share their teenagers’ doubts as to whether any of this stuff is relevant in any case.”
Euclid (Book 1, Definition 22)
“Of quadrilateral figures, a square is that which is both equilateral and right-angled; an oblong that which is right-angled but not equilateral; a rhombus that which is equilateral but not right-angled; and a rhomboid that which has opposite sides and angles equal to one another but is neither equilateral nor right angled. And let quadrilaterals other than these be called trapezia.”
Different Types of Quadrilaterals
RECTANGLE is a four-sided shape with four right angles, and includes:
SQUARE which has four right angles AND four equal sides
OBLONG which has four right angles BUT two pairs of equal sides (not four equal sides)
RHOMBUS is a four-sided shape with four equal sides BUT no right-angles
RHOMBOID is a four-sided shape with two pairs of equal sides, and opposite angles are equal (also a PARALLELOGRAM)
TRAPEZIUM is a four-sided shape with one pair of parallel sides (called a TRAPEZOID in America!)
TRAPEZOID is a four-sided shape with no parallel sides (called a TRAPEZIUM in America!)