Archive for the ‘Uncategorized’ Category
Is time spent on arithmetic during grades 3, 4 and 5 wasted?
Posted by: Gary Ernest Davis on: April 4, 2011
The answer depends on what we mean by “arithmetic”. If we mean learning algorithms for addition, subtraction, multiplication and division, and sundry other taught methods, then the answer seems to be yes. If we mean working on sensible and real arithmetic problems – not make believe problems – then the answer seems to be no: […]
I (x^2 + 9y^2/4 + z^2 – 1)^3 == x^2z^3 + y^2z^3/9 math
Posted by: Gary Ernest Davis on: April 3, 2011
The equation defines a set of points in space that forms a lovely surface, hospital dear to the of all mathematicians: Mathematica code The image above was produced using Mathematica. Here is the (one line) code: ContourPlot3D[(x^2 + 9*y^2/4 + z^2 – 1)^3 == x^2*z^3 + y^2*z^3/9, {x, -3/2, 3/2}, {y, -3/2, 3/2}, {z, […]
