What is zero? Zero and place value
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 [...]
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 [...]
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 [...]
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 [...]
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 [...]
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. Whole numbers are the numbers you learned when you were first learning to count - one, two, three, four, five and so [...]
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 [...]
A fraction of a pie: What are fractions? We started with whole numbers When we first thought about the number line, we counted only in whole numbers - we went straight from zero [...]