Math
Perimeter
The total distance around the outside edge of a 2D shape.
Evaporation
The process where a liquid slowly turns into a gas when heated.
Heart Rate
The number of times your heart beats in one minute.
Empire
A large group of countries or territories ruled by a single king, queen, or government.
Noun
A part of speech used to name a person, place, thing, or idea.
Prime Number
A whole number greater than 1 that can only be divided by 1 and itself.
Gravity
The invisible force that pulls objects down toward the center of the Earth.
Dehydration
A harmful condition caused by losing more water from your body than you drink.
Revolution
A rapid and often violent attempt by a large group of people to change their country's political system.
Simile
A figure of speech that compares two different things using the words "like" or "as".
Probability
The measure of how likely it is that an event will happen.
Molecule
A group of two or more atoms chemically joined together.
Stamina
The physical ability to maintain effort or exercise for a long time.
Treaty
A formal written agreement between countries to end a war or make peace.
Synonym
A word that has the same or almost the same meaning as another word.
Equation
A mathematical statement showing that two expressions are equal using an equals sign ($=$).
Friction
The force that slows down moving objects when two surfaces rub together.
Warm-Up
Light exercises done before sports to prepare your muscles and avoid injuries.
Cold War
The period of high political tension and threat of war between the USA and USSR after World War II.
Protagonist
The main character or central figure in a story, novel, or play.
Volume
The amount of three-dimensional space an object takes up.
Ecosystem
A community of living plants and animals interacting with their environment.
Agility
The physical ability to change body position quickly and easily while staying in control.
Propaganda
Information, pictures, or rumors spread deliberately to influence public opinion or political beliefs.
Theme
The main idea, underlying message, or lesson behind a story or piece of literature.