Exponents – numbers and math
This is a square. The darker purple line is the perimeter of the square. Using exponents is a short way of saying "multiply the number by itself." The little number [...]
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07, 2017
29
07, 2017
Which one is the denominator? Fractions
A pie cut into thirds The denominator of a fraction is the number on the bottom (the top is the numerator). In the fraction 1/2, the denominator is 2. In the fraction 45/66, the denominator [...]
29
07, 2017
Decimals and fractions – Numbers
A number line is infinite in both directions. Decimals, like fractions, are a way of describing points on the number line that fall in between the whole numbers. If you were using fractions, you'd [...]
29
07, 2017
Common denominator – fractions
A fraction of a pie If you want to add two fractions together, both fractions must have the same denominator. That's okay if you want to add 1/9 and 4/9 = 5/9. But what if [...]
29
07, 2017
Big numbers – billions and trillions
An infinite distance: stars in the sky Why do we use exponents? Some numbers are so big that it's hard to write them in the regular way. The number line [...]
29
07, 2017
What is area? Simple geometry
Calculating the area of your room. The area of a room is the size of the floor. Suppose you wanted to find out whether your room was really bigger than [...]
29
07, 2017
What is a triangle? Simple geometry
This is an equilateral triangle. A triangle is any set of three points on a plane and the lines connecting those points to each other, as long as the three points aren't all on the [...]
29
07, 2017
What is a trapezoid? Simple geometry
This is a trapezoid. A trapezoid is a kind of quadrilateral that has at least two sides that are parallel to each other. A parallelogram is a trapezoid that has two pairs of parallel [...]
29
07, 2017
What is a square? Simple geometry
This is a square. The darker purple line is the perimeter of the square. A square is a flat shape, in one plane, defined by four points at the four corners. A square [...]
29
07, 2017
Area of a sphere – Volume of a sphere
This is a sphere. A sphere is a three-dimensional circle. Or you could say that a sphere is the set of all the points that are at the same distance from the center [...]
