# Math

Q:

## What are compatible numbers in the third grade?

A:

In the third grade, compatible numbers are estimated figures that are used to make mental arithmetic simpler. Compatible numbers are very close to the actual numbers and yield a similar result with less work.

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• ## Algebra

• #### Q:Where did algebra come from?

A: Algebra has been developed over thousands of years in several different countries. The earliest methods for solving mathematical problems with one or more unknown quantities come from ancient Egypt. The word "algebra" itself is derived from the title of Baghdad mathematician Al-Kwarizmi's 9th century book, "Hidab al-jabr wal-muqubala."
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• #### Q:What is the procedure for solving equations graphically?

A: To solve an equation in one variable graphically, first manipulate the equation to put it in the form f(x) = 0, where x represents the variable present in the equation. Then use mathematical software, a graphing calculator or graph paper to plot the line y = f(x). The solution to f(x) = 0 is the point or points at which the line crosses the x-axis.
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• #### Q:How is algebra used in everyday life?

A: People use algebra in their daily lives when they make decisions about health, fitness, financial and money matters and when cooking. Algebra involves the use of known variables and fixed numbers in equations to find the values of unknown numbers.
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• #### Q:What is a formula equation?

A: A formula equation is a visual representation of a reaction using chemical formulas. A chemical formula is an expression that states the number and types of atoms that make up any given molecule using the symbols for the elements and sub-scripted numbers.
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• #### Q:What does equation mean?

A: The word "equation" is related to the word "equals" and generally describes a state of balance or equilibrium, according to Dictionary.com. Equations are commonly used in mathematics and chemistry.
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• #### Q:Why is math important in life?

A: Math is important in life because it is used to perform many different daily tasks, such as telling time, reading an odometer, counting change and to make strategic decisions in one's work life. Similarly, nearly every profession uses some form of math. For example, nurses, engineers, bank tellers, pharmacists and stock market analysts use math every day to perform their professional duties well.
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• ## Arithmetic

• #### Q:Who created numbers?

A: The Babylonian society used a cuneiform method of writing that included numerical characters; this is the earliest-known form of numbers, meaning that, as far as humans know, the Babylonians created numbers. This system of numerical writing is about 5,000 years old, and it is a base-60 system as opposed to a base-10 system, which is what most humans use for counting and mathematics in the modern world. Time measurements, in which an hour consists of 60 minutes and a minute consists of 60 seconds, are one example of a sexidecimal, or base-60, numerical system that is alive and well in the modern world.
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• #### Q:How much money is in a roll of quarters?

A: In the United States, a roll of quarters is worth \$10. It includes 40 quarters.
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• #### Q:What is the history of the square root in mathematics?

A: According to Saint Louis University, the ancient Egyptians created the square root and most likely used it for architecture, building pyramids and other daily activities that required math. Most of the present-day knowledge of Egyptian math comes from papyri written during the 12th dynasty.
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• #### Q:In mathematical terms, what does "factor" mean?

A: A factor is a number or expression that divides another number or expression evenly without a remainder. For instance, two, four, five and 10 are factors of 20 because 20 can be divided by all those smaller numbers an exact number of times. Prime numbers are positive integers greater than one that have exactly two factors. A composite number has more than two factors.
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• #### Q:How do you change a fraction to a percent?

A: A fraction is converted to a percentage by first expressing the fraction with a denominator of 100, then writing the numerator with a percent sign behind it. Some fractions can be easily converted if basic ratio equivalents are known.
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• #### Q:What does "median" mean in mathematics?

A: The median is the number that is in the middle in a list of sorted numbers. To find the median, the numbers must be sorted from lowest to highest.
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• ## Calculus

• #### Q:What are some common Pythagorean triples?

A: A Pythagorean triple is a set of three positive integers, (a, b, c), such that a right triangle can be formed with the legs a and b and the hypotenuse c. The most common Pythagorean triples are (3, 4, 5), (5, 12, 13), (8, 15, 17) and (7, 24, 25).
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• #### Q:How are logarithms used in the world?

A: A few examples of how logarithms are used in the real world include measuring the magnitude of earthquakes or the intensity of sound and determining acidity. A logarithm explains how many times a number is multiplied to a power to reach another number. It is expressed as loge(x) and is commonly written as ln(x).
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• #### Q:How do you calculate bulk density?

A: To calculate bulk density, simply weigh the sample and divide its mass by its volume. Bulk density is commonly used when referring to solid mixtures like soil. Just like particle density, bulk density is also measured in mass per volume.
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• #### Q:What are the meanings of "sin", "cos", "tan", "csc", "sec" and "cot"?

A: The abbreviations "sin," "cos," "tan," "csc," "sec" and "cot" stand for the six trigonometric functions: sine, cosine, tangent, cosecant, secant and cotangent. Each function represents a particular relationship between the measure of one of the angles and the ratio between two sides of a right triangle.
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• #### Q:How is calculus used in medicine?

A: According to class notes from Bunker Hill Community College, calculus is often used in medicine in the field of pharmacology to determine the best dosage of a drug that is administered and its rate of dissolving. Usually, the drug is slowly dissolved in the stomach.
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• #### Q:How many millimeters equal 1 meter?

A: One thousand millimeters is equal to 1 meter. The meter is the standard unit of length in the International System of Units, also known as the metric system. "Metre" is the standard spelling for all English-speaking countries except the United States. "Meter" is the accepted U.S. spelling.
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• ## Data Graphs

• #### Q:What is a segmented bar graph?

A: A segmented bar graph is similar to regular bar graph except the bars are made of different segments that are represented visually through colored sections. A segmented bar graph is sometimes known as a stacked bar graph, and it offers greater detail about data sets.
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A: The primary advantage of using a graph or chart in a presentation is that they help the audience to visualize the point of the presentation. Graphs emphasize the main point, make the data more convincing, provide a compact way of presenting information and help audiences stay engaged. Disadvantages of graphs include being time consuming to construct and costly to produce. They also require technology that some may lack.
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• #### Q:How is a tally chart made?

A: To make a tally chart, single lines are drawn next to one another until reaching five, where the fifth line crosses the four other lines diagonally. This is a simple charting method that can be used quickly for surveys or other needs.
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• #### Q:What is numerical data?

A: Numerical data is data that is expressed with digits as opposed to letters or words. For example, the weight of a desk or the height of a building is numerical data.