## Tangents – trigonometry – math

Tangents: This line is tangent to a circle. What is a tangent? A tangent, like a sine or a cosine, is a mathematical way of thinking about a kind of movement that happens [...]

29
07, 2017

Tangents: This line is tangent to a circle. What is a tangent? A tangent, like a sine or a cosine, is a mathematical way of thinking about a kind of movement that happens [...]

29
07, 2017

Sine wave In order to save energy, many, many things in nature move in a kind of repeated pattern we call a sine wave: water waves, sound waves, light waves, [...]

29
07, 2017

An infinite distance: stars in the sky Since the time of the Sumerians, about 3000 BC, scientists have studied the stars and the planets. They've tried to figure out the patterns in the movements of [...]

29
07, 2017

Right triangle and cosine What is a cosine? A cosine, like a sine, is a mathematical way of thinking about a kind of movement that happens in nature. A cosine is [...]

29
07, 2017

A math problem showing place value How can you add big numbers without an abacus? You still group the sheep (or whatever) just as you did when you were using the abacus, but [...]

29
07, 2017

A boy walking backwards Subtracting numbers is just the same as adding them, only walking the other way along the number line. To subtract 3 from 8, you start on the number [...]

29
07, 2017

Walk along a chalk line Multiplying numbers is like jumping along the number line, with all your jumps the same size. It's the same thing as addition, except that you repeat [...]

29
07, 2017

Walk along a chalk line The four basic things you do with numbers are addition, subtraction, multiplication, and division. Each of these is basically a way of describing how fast you are moving along [...]

29
07, 2017

Walk along a chalk line To get to understand the number line better, mark out a line on the playground or on the sidewalk outside your house with chalk. At the middle of [...]

29
07, 2017

How many of these things can I fit into these boxes? Division is a way of answering the question: how many of these things can I fit into that box? [...]