iWorth's Blog:

If you have a set of data, say exam marks or heights, and are told to find the ‘average’. So what’s an average? An average indicates the typical value of a set of data, and it could be done in three different ways, which are  are mean, median and mode. (a)The median The median is the middle number. The data is arranged in order from the smallest to the largest; the middle number is then selected. This is really the central number of the range and is called the median. If there are two ‘middle’ numbers, the median is in the middle of these two numbers. (b)The mean The mean is the most common measure of average. All the data is added up and the total divided by the number of items. This is called the mean and is equivalent to sharing out all the data evenly. (c)The mode The number of items which occurs most frequently in a frequency table is selected. This is the most popular value and is called the mode (from the French ‘à la mode’ meaning ‘fashionable’). Each...

When we draw a solid on paper we are making a 2-D representation of a 3-D object. Here are two pictures of the same cuboid, measuring 4x3x2 units. cuboid on ordinary squared paper and on isometric paper The isometric paper has a grid of equilateral triangles instead of square, this isometric view can be obtained by choosing viewing direction in such a way that the angles between the projection of x, y, and z axes are all the same, or 120. The dimensions of the cuboid cannot be taken from the first picture but they can be taken from the picture drawn on isometric paper. Instead of isometric paper you can also use 'triangular dotty' paper. triangular dotty paper Be careful to use it the right way round.

Transforming shapes Reflection : With reflection the object and its image are congruent because they are the same size and shape. Rotation : You need three things to describe a rotation: (a) the centre (b) the angle (c) the direction (e.g. clockwise). Enlargement : The scale factor of an enlargement can be found by dividing corresponding lengths on two pictures. Reduction : Even though a shape has undergone a reduction, mathematicians prefer to call it an enlargement with a fractional scale factor. Translation : A translation is simply a 'shift'. There is no turning or reflection and the object stays the same size. Translations are described by vector. In a vector the top number gives the number of units across (positive to the right) and the bottom number gives the number of units up/down (positive upwards). Translation with a vector Tessellations : A tessellation is formed when a shape (or shapes) fit together without gaps to cover a surface, like jigsa...