ARITHMETIC
Mathematics is like building with magical blocks. Once you learn the four basic ways to put them together and take them apart, you hold the keys to the entire universe.
The Art of Combining
Addition (+) is the act of bringing things together. If you have 3 apples and find 2 more, you simply count them all as one big group to get 5. Subtraction (-) is the exact opposite—it is the art of taking things away or finding the difference between two groups.
Base-10 Engine
Physical Place Value
Boxes of Ten (Place Value)
Because humans have ten fingers, we designed our math to roll over every time we hit 10. Imagine you are packing toys into boxes, and each box can only hold exactly 10 toys.
If you have 12 toys, you fill up 1 whole box, and you have 2 toys left over sitting outside.
Fast-Forward & Sharing
Multiplication
Multiplication is just a shortcut for adding the same number over and over again. Instead of writing 3 + 3 + 3 + 3, we just say "four groups of three" (4 × 3).
Division
Division is the act of fair sharing. If you have 12 cookies and 3 friends, how many cookies does each friend get so that everyone is perfectly equal? (12 ÷ 3 = 4).
The Rules of the Game
When you have a long math problem with lots of different symbols, you can't just read it left-to-right like a book. Mathematicians agreed on a strict order to solve things so that everyone gets the exact same answer.
Parentheses ( )
Always solve whatever is trapped inside the brackets first.
Exponents x²
Handle the tiny floating numbers next.
Multiply & Divide × ÷
Read from left to right and do all multiplication and division.
Add & Subtract + -
Finally, clean up the rest by adding and subtracting left to right.
Unit Complete!
You've mastered the building blocks of math.