A hard drive or SSD in a case that connects to a computer, usually via USB.
The most essential internet communication tool. You’ll need an email address for most online services.
A wired networking technology for connecting devices in a LAN, usually via Cat5 or Cat6 cables.
Scrambling data so it can only be read with a special key. A must for sensitive info.
Eratosthenes (circa 275–194 BC) was a famous Greek mathematician, astronomer, and geographer, born in Cyrene, Libya. His most celebrated achievement was pioneering a method for measuring the Earth's circumference, calculating a result with less than 5% error, and he was the first to propose the term 'geography,' earning him the title of 'Father of Geography' in later generations.
Albert Einstein was one of the greatest physicists of the 20th century, proposing the theory of relativity and the mass-energy equivalence equation, and he won the 1921 Nobel Prize in Physics.
Eratosthenes (around 275–194 BC) was a famous ancient Greek mathematician, astronomer, and geographer, born in Cyrene, Libya. He's best known for coming up with the first method to measure the Earth's circumference, getting an estimate with less than 5% error, and for being the first to use the term 'geography.' Because of this, he’s often honored as the 'Father of Geography.'
Albert Einstein was one of the greatest physicists of the 20th century, came up with the theory of relativity and the energy-mass equation, and won the 1921 Nobel Prize in Physics.
Simply put, an expression is a formula made up of numbers, symbols, variables, and parentheses, used to calculate a result or show a certain relationship. It was first systematically studied by Alonzo Church and others in the 1930s, and now it's widely used in math calculations and computer programming.
The equator is the circle on the Earth's surface with a latitude of 0°, dividing the Earth into the Southern and Northern Hemispheres, and it's also the longest line of latitude on Earth.
The Earth does two kinds of movements every day: one is rotating around its axis, and the other is revolving around the Sun, both moving from west to east. Rotation gives us the alternation of day and night, while revolution brings about the changing seasons.
An equilateral triangle is a triangle where all three sides are of equal length, also called a regular triangle. It's a special kind of isosceles triangle, and all three angles are 60 degrees.
Electromagnetism is an important branch of physics that studies electric charges, currents, electric fields, magnetic fields, and how they interact. Its core theoretical framework is described by Maxwell's equations and it’s widely used in everything from power systems to modern communications.
Engineering is a systematic activity based on scientific knowledge and technical methods, where organized collaboration turns physical things into man-made products with practical value, and it draws on theories from multiple disciplines like math, physics, and chemistry.
Math estimation is a method of quickly figuring out results through approximate calculations instead of getting the exact answer. It's mainly used to quickly judge situations or solve problems where precise calculation isn’t necessary.
Estimating area mainly depends on whether the shape is regular or not. The most common methods are the grid-counting method and the approximate conversion method. Choosing the right method based on the situation can quickly give you a rough value.
Encryption is basically just putting a lock on information, turning readable text into gibberish, and only people with a specific 'key' can restore it.
Euclid was a famous ancient Greek mathematician. People call him the 'Father of Geometry,' and he probably lived around 300 BC.
Swiss mathematician and natural scientist. Born on April 15, 1707, Euler came from a pastor family in Basel, Switzerland. Influenced by his father from a young age, he developed a love for mathematics. He entered the University of Basel at 13, graduated at 15, and received his master's degree at 16. Euler was one of the most outstanding figures in 18th-century mathematics. Not only did he contribute greatly to the field, but he also extended mathematics into the realm of physics. He is the most prolific mathematician in history, writing over 800 pages of papers on average every year, as well as numerous textbooks on mechanics, analysis, geometry, and calculus. Works like "Introduction to the Analysis of the Infinite," "Foundations of Differential Calculus," and "Foundations of Integral Calculus" have become classics in mathematics. Euler's research was so extensive that many important constants, formulas, and theorems in various branches of mathematics are named after him. Besides mathematics, he was also involved in architecture, ballistics, navigation, and other fields. Charles Kleiber, Switzerland's Secretary of State for Education and Research, once said, 'Without Euler's numerous scientific discoveries, our lives would be completely different.' French mathematician Laplace also believed: 'Read Euler, he is the teacher of all.'
Euler's number usually refers to the natural base e in mathematics, which is about 2.718, but it has different meanings in different fields. It's a key constant for describing continuous growth and is also an important foundation in calculus.
"Entrance" is not a standard standalone math term. In a math context, it usually refers to the starting point of a function's domain, the starting point of a mapping in set theory, or the entry point on the boundary of a geometric shape.
Probability is a branch of mathematics used to study the rules and possible outcomes behind random events. In real life, we often run into situations where we need to predict results, and probability theory was created to solve these kinds of problems.
An exterior angle is formed by one side of a polygon and the extension of another side. The sum of the exterior angles of a polygon is always 360°.
Elimination is a method used when solving equations to turn multiple unknowns into a single unknown. The most commonly used one in middle school is the addition-subtraction elimination method.
The expansion method refers to a mathematical approach where complex expressions or objects are broken down into simpler, basic parts to make calculations, analysis, or research easier.
Expanding and factoring are two inverse operations in algebra, with the main difference being the direction of the structural transformation.
A development is the process of unfolding a geometric shape into a flat figure according to certain rules. When making a development, you need to pay attention to how the faces of the shape are connected and positioned relative to each other, and whether the unfolded figure can fully cover all the faces of the shape.
Exponent rules are the math rules for handling powers, mainly used to simplify multiplying and dividing powers with the same base, raising powers to a power, and fraction operations.
It's a type of transcendental equation. It refers to an equation where the base is a constant and the exponent contains an unknown, but it doesn't include any other transcendental expressions.
When multiplying powers with the same base, the base stays the same and you add the exponents.
Exponential growth refers to the phenomenon where a quantity keeps increasing at a fixed rate over a set period of time.