Maths and science words, explained

Maths

• Acute angle: An angle that measures less than 90 degrees.
• Addend: One of the numbers you add together.
• Angle: The amount of turn between two lines that meet at a point.
• Area: How much flat space a shape covers.
• Array: Objects arranged in equal rows and columns.
• Capacity: How much a container can hold.
• Circumference: The distance around a circle.
• Decimal: A number with a decimal point, where the digits after the point are tenths, hundredths and so on.
• Denominator: The bottom number of a fraction: how many equal parts make the whole.
• Diameter: The distance across a circle through its center.
• Difference: The answer when you subtract one number from another.
• Digit: One of the ten symbols 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 used to write numbers.
• Equivalent fractions: Fractions that look different but name the same amount.
• Even number: A whole number that can be split into two equal groups with none left over.
• Expanded form: A way of writing a number as the sum of the value of each digit.
• Factor: A whole number that divides another whole number exactly, with nothing left over.
• Fraction: A number that names part of a whole or part of a group.
• Improper fraction: A fraction whose numerator is greater than or equal to its denominator.
• Inequality: A statement that two amounts are not equal, using symbols such as <, > or ≠.
• Integer: Any whole number, its opposite, or zero: ..., −2, −1, 0, 1, 2, ...
• Line plot: A graph that shows data on a number line, with an X above the number for each data point.
• Mass: The amount of matter in an object.
• Mean: The average: add all the values, then divide by how many there are.
• Median: The middle value when the data is put in order.
• Mixed number: A number made of a whole number and a fraction.
• Mode: The value that appears most often in a set of data.
• Multiple: The result of multiplying a number by a whole number.
• Negative number: A number less than zero, written with a minus sign.
• Numerator: The top number of a fraction: how many equal parts you have.
• Obtuse angle: An angle that measures more than 90 degrees and less than 180 degrees.
• Odd number: A whole number that leaves 1 left over when split into two equal groups.
• Parallel lines: Lines in the same flat surface that stay the same distance apart and never meet.
• Pattern rule: A description of how a pattern starts and how it changes each time.
• Percent: A part out of 100. The sign is %.
• Perimeter: The distance all the way around the outside of a shape.
• Perpendicular lines: Two lines that meet to form a right angle.
• Place value: The value a digit has because of where it sits in a number.
• Polygon: A closed flat shape made of straight sides.
• Prime number: A whole number greater than 1 with exactly two factors: 1 and itself.
• Prism: A solid shape with two identical, parallel bases and flat sides that are rectangles.
• Probability: How likely something is to happen.
• Product: The answer when you multiply numbers.
• Pyramid: A solid shape with a flat base and triangle faces that meet at one point.
• Quadrilateral: A polygon with exactly 4 sides.
• Quotient: The answer when you divide.
• Radius: The distance from the center of a circle to its edge.
• Ratio: A comparison of two amounts, written with a colon, the word to, or as a fraction.
• Right angle: An angle that measures exactly 90 degrees, like the corner of a square.
• Rounding: Changing a number to a nearby, simpler number.
• Sum: The answer when you add numbers.
• Symmetry: When one half of a shape is a mirror image of the other half.
• Unit rate: A rate that compares an amount to exactly 1 of something.
• Variable: A letter or symbol that stands for a number you don't know yet, or one that can change.
• Vertex: A point where two or more lines or edges meet. The plural is vertices.
• Volume: How much space a solid object takes up.

Science

• Adaptation: A body part or behaviour that helps a living thing survive where it lives.
• Circuit: A complete loop that electricity can flow around.
• Condensation: When a gas cools and turns into a liquid, such as water vapor into drops of water.
• Conductor: A material that lets electricity or heat move through it easily.
• Consumer: A living thing that gets its energy by eating other living things.
• Decomposer: A living thing that breaks down dead plants and animals and returns nutrients to the soil.
• Density: How much mass is packed into a certain amount of space.
• Ecosystem: All the living things in an area and the nonliving things they interact with.
• Erosion: When wind, water or ice carry away bits of rock and soil.
• Evaporation: When a liquid turns into a gas, such as water into water vapor.
• Fair test: An experiment where you change only one thing and keep everything else the same.
• Food web: A diagram of all the food chains in an ecosystem and how they link.
• Force: A push or a pull.
• Fossil: The preserved remains or traces of a living thing from long ago.
• Friction: A force that slows things down when two surfaces rub together.
• Germination: When a seed begins to grow into a new plant.
• Gravity: The force that pulls objects toward each other, such as toward the center of Earth.
• Habitat: The place where a plant or animal naturally lives and finds what it needs.
• Hypothesis: A testable guess about what will happen and why.
• Insulator: A material that does not let electricity or heat move through it easily.
• Lever: A simple machine: a bar that turns on a point called the fulcrum.
• Life cycle: The stages a living thing goes through from birth to having young of its own.
• Magnet: An object that attracts iron and some other metals, and that has a north and a south pole.
• Mineral: A solid substance found in nature that was never alive and has a definite chemical makeup.
• Orbit: The curved path of one object around another in space.
• Phases of the Moon: The changing shape of the lit part of the Moon we see from Earth.
• Photosynthesis: How green plants make their own food using light.
• Pollination: The moving of pollen from one part of a flower to another so that seeds can form.
• Precipitation: Water that falls from clouds to the ground as rain, snow, sleet or hail.
• Predator: An animal that hunts and eats other animals.
• Prey: An animal that is hunted and eaten by another animal.
• Producer: A living thing that makes its own food, usually a plant.
• Revolution: One full trip of an object around another, such as Earth around the Sun.
• Rotation: The spinning of an object around its own axis.
• Season: One of the four parts of the year, spring, summer, fall and winter, each with its own typical weather.
• Shadow: A dark area made when an object blocks light.
• States of matter: The forms matter takes: solid, liquid and gas.
• Vibration: A quick back-and-forth movement. All sounds are made by vibrations.
• Water cycle: The way water moves between the land, the oceans and the air, over and over.
• Weathering: The slow breaking down of rock into smaller pieces by wind, water, ice or plants.