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 [...]
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 [...]
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? [...]
A number line is infinite in both directions. When people say that addition is commutative, that means that it doesn't matter what order you add up the numbers. 3 + 6 [...]
A number line is infinite in both directions. Adding numbers is like walking along a path, the number line. To add two small numbers, like 7 + 4, you can just [...]
A number line is infinite in both directions. Whole numbers are the numbers you learned when you were first learning to count - one, two, three, four, five and so [...]
Each penny is 1% of a dollar. Percent comes from the Latin words "per cent". That means "out of a hundred," like there are 100 cents in a dollar. So [...]
A pie cut into thirds The numerator of a fraction is the number on the top, just as the denominator is the number on the bottom. In the fraction 1/2, the numerator is one, and in [...]
Earthquake in Peru - we measure earthquakes using logarithms What are logarithms? Logarithms are a way of writing numbers using exponents. "Log 100" means the exponent you'd need to use to get 100 [...]
Infinity: A number line is infinite in both directions. No end to the number line When we think about the number line, we can see that there's no end to it [...]
