Algebra

Algebra is a kind of math. In algebra, we use letters like x or y to stand for numbers. These letters are called variables. We use them to solve puzzles and find missing numbers. Algebra helps us answer questions like, 'What number plus 3 equals 10?' The answer is 7! Algebra is used all over the world. People have been doing algebra for a very long time.

What Is a Variable?

A variable is a letter that stands for a number. The letter x is used a lot. For example, x + 2 = 5. Here, x is a missing number. We need to figure out what x is. If we take 2 away from 5, we get 3. So x is 3! Variables make it easy to write math problems. They help us think about numbers we do not know yet.

Why We Use Algebra

Algebra is useful in real life. It helps us share things fairly. It helps us build houses and bridges. It helps us fly planes and send rockets to space. Shop keepers use algebra to count money. Cooks use it to change recipes. Even video games use algebra to move things on the screen. Learning algebra is like learning a new way to solve puzzles.

Fun Facts

• The word algebra comes from an old Arabic word, 'al-jabr', which means 'putting back together'.
• A man named al-Khwarizmi wrote one of the first books about algebra over 1,200 years ago.
• The equals sign (=) was made in 1557 by a man named Robert Recorde because he got tired of writing 'is equal to'.

Did You Know?

You already do algebra without knowing it! When you think, 'How many more cookies do I need to have 10?' you are solving an algebra problem in your head.