Grace Imson, MA
Math Instructor, City College of San Francisco
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Co-authored Articles (237)
The Trachtenberg Method: Learn to Calculate Multi-Digit Numbers Quickly
Quick, easy techniques to add, multiply, and divide without breaking a sweat Do you wish you could do more math in your head? Do you find conventional arithmetic difficult? Then the Trachtenberg method is perfect for yo...
How to
Use an Abacus
The abacus (the suanpan is the most useful variety) is a deceptively simple calculating tool still used all over the world. It's a useful learning device for the visually impaired, as well as for anyone who wants to lear...
How to
Do Long Division
A part of basic arithmetic, long division is a method of solving and finding the answer and remainder for division problems that involve numbers with at least two digits. Learning the basic steps of long division will al...
How to
Calculate Standard Deviation
Standard deviation tells you how spread out the numbers are in a sample. Once you know what numbers and equations to use, calculating standard deviation is simple!
How to
Convert from Decimal to Binary
The decimal (base ten) numeral system has ten possible values (0,1,2,3,4,5,6,7,8, or 9) for each place-value. In contrast, the binary (base two) numeral system has two possible values represented as 0 or 1 for each pla...
How to
Do Long Multiplication
Long multiplication can seem very intimidating, especially if you're multiplying two numbers that are pretty large. If you take it step by step, though, you'll be able to do long multiplication in no time. Get ready to a...
How to
Calculate the Circumference of a Circle
Need to know how to find the circumference of a circle? Can't remember the circumference formula? Don't sweat it—we've got you covered. If you know the diameter, simply plug it into this formula: '''C=πd'''. Were you...
How to
Do Division
Division is one of the 4 major operations in arithmetic, alongside addition, subtraction, and multiplication. In addition to whole numbers, you can divide decimals, fractions, or exponents. You can do long division or, i...
How to
Convert Radians to Degrees
Radians and degrees are both units used for measuring angles. As you may know, a circle is comprised of 2π radians, which is the equivalent of 360°; both of these values represent going "once around" a circle. Therefo...
How to Use the Percent Change Formula
Easily find percent increase or decrease with this simple equationLooking at the change in percent of a number, as opposed to the change in value, can give you a more useful representation of how something has increased...
How to Calculate the Slope of a Line
Learn to calculate the slope of a line with these simple methods If you’re taking algebra, finding the slope of a line is an important concept to understand. But there are multiple ways to find the slope, and your teac...
How to
Calculate Ratios
Ratios are mathematical expressions that compare two or more numbers. They can compare absolute quantities and amounts ''or'' can be used to compare portions of a larger whole. Ratios can be calculated and written in sev...
How to
Calculate the Area of a Circle
Need to know how to find the area of a circle? This is a common geometry problem and figuring out the answer is pretty easy. In most cases, you can use the simple formula A=\pi r^2. If you don't know the radius, don't w...
How to Find Horizontal Asymptotes: Rules for Rational Functions
If you see a dashed or dotted horizontal line on a graph, it refers to a horizontal asymptote (HA). In a rational function, an equation with a ratio of 2 polynomials, an asymptote is a line that curves closely toward the...
How to
Find the Domain of a Function
The domain of a function is the set of numbers that can go into a given function. In other words, it is the set of x-values that you can put into any given equation. The set of possible y-values is called the range. If y...
How to
Calculate Percentage Increase
Knowing how to calculate percentage increase is useful in a variety of situations. For instance, even when watching the news, you'll often hear a change described in large numbers without any percentage to give them cont...
How to
Find the Y Intercept
On their own, y-intercepts aren’t complicated at all—they’re simply points where the graph of the equation intersects with the Y-axis. But how are you supposed to find a y-intercept when you only have a limited amo...
How to
Convert Milliliters (mL) to Grams (g)
center Converting from milliliters (mL) to grams (g) is more complicated than plugging in a number, because it converts a volume unit, milliliters, to a mass unit, grams. This means each substance will have a different f...
How to
Calculate Volume in Litres
A liter (or litre) is a metric unit used to measure volume or capacity. Liters are a common measurement often used to measure beverages and other liquids, such as a 2 liter bottle of soda. Sometimes you will need to calc...
How to
Do Double Digit Multiplication
'''Double digit multiplication is simply single-digit multiplication done twice.''' It starts off just the same with multiplying the numbers in the ones place, and then you add a second round of multiplication using the ...
