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 TOPICS This page:   multiplication    Search   Dr. Math See also the Dr. Math FAQ:   multiplication facts and   order of operations Internet Library:   multiplication T2T FAQ:   learning to multiply ELEMENTARY Arithmetic    addition    subtraction    multiplication    division    fractions/decimals Definitions Geometry    2-dimensional      circles      triangles/polygons    3D and higher      polyhedra Golden Ratio/ Fibonacci Sequence History/Biography Measurement    calendars/      dates/time    temperature    terms/units Number Sense/ About Numbers    infinity    large numbers    place value    prime numbers    square roots Projects Puzzles Word Problems Browse Elementary Multiplication Stars indicate particularly interesting answers or good places to begin browsing. Selected answers to common questions:     Flashcards/worksheets on the Web.     Learning to multiply.     Least common multiple, Greatest common factor.     Number sentences.     Order of operations. Associative, Distributive Properties [9/5/1996] Please explain the associative and distributive properties. Basic Real Number Properties [07/31/1997] I need information about basic real number properties: associative, commutative, closure, identity, inverse, distributive. Cross-Multiplication [08/04/2002] Can you explain cross-multiplication? Distributive Property, Illustrated [09/28/2001] How can I show (12*2) + (12*3) using the distributive property? Finger Multiplication for the 9s [06/10/1998] Do you have any tricks for learning the times table for 9? Help With Multiplication and Percents [11/11/1996] Can you help me with multiplication so that I can better understand percents? Homeschooling Multiplication [7/7/1996] My son can't seem to memorize his times tables and therefore can't divide. Lattice Multiplication [8/30/1996] Can you please explain the lattice method of multiplication? Lattice Multiplication Explained [10/20/1999] Can you explain why the lattice method of multiplication works? Learning Only 36 of the Times Tables [11/04/2001] My mother says that I only need to know 36 of the times tables because problems can be reversed to a higher problem. What are the 36 problems? Least Common Multiple Puzzle [03/24/2003] What is the smallest number divisible by 1,2,3,4,5,6,8,9,10 that is not 3600? Manipulating Positive and Negative Numbers [8/9/1996] Could you explain the rules for adding, subtracting, multiplying, and dividing positive and negative numbers? Memorizing Multiplication Facts [02/25/2001] I can't remember my multiplication facts. I have flash cards, but they don't work... Memorizing Multiplication Tables [01/06/1997] I am having a problem memorizing my times tables. How can I do this easily? Multiples and Factors [06/02/2003] What is the difference between multiples and factors? Multiples of 9 Number Puzzle [03/23/2003] If you take a two-digit number, add the digits, and subtract the sum from the original number, why is the answer always a multiple of 9? Multiplication's Multiple Meanings: Unified by the Distributive [01/01/2015] Area? Matrix multiplication? Scaling and rotation? A parent seeks a global understanding — or at least some internal consistency — as to what ties together all the operations called "multiplication." Building up from the natural numbers, where multiplication is repeated addition (MIRA), Doctor Peterson teases out two common threads. Multiplying by 0 [03/09/2001] Why, when multiplying any number by 0, do you get 0? Multiplying by 9, Step by Step [11/05/2001] I need help with 9 x 240,531. Multiplying Two 2-Digit Numbers [03/25/1997] How do you do 28 x 24? Odd and Even Multiplication [02/17/1999] Is it true that multiplying an even number and an odd or even number always gives an even number? Order of Operations for Solving Equations [10/12/1995] How would you multiply a question like this: -2(x-y)^2 ? Order Of Operations in Four Steps [02/15/1998] I need help figuring out what operation to do first. Prime Numbers [01/31/1997] What are the prime numbers and why are they prime numbers? Properties of Real Numbers [05/20/1997] What are the associative, the commutative, and the zero product properties? Reciprocals [12/19/1996] What is the use of reciprocals? Rectangles and Factors [09/09/1998] How many rectangles can you make with 10 small squares? 5 small squares? 12 small squares? Remembering Multiplication Tables [2/5/1996] Is there an easy way to remember multiplication tables? Running Laps and LCMs [02/11/1999] Bill, Bob, and John run 1/3rd, 1/5th, and 1/6th of a lap per minute, respectively. How many laps do they need to run to cross the finish line at the same time? Russian Peasant Method of Multiplication [10/07/1998] I understand the 'Russian peasant' method of multiplication, but not why it works. Russian Peasant Multiplication [02/26/2001] Can you explain why the Russian Peasant algorithm works? How do the numbers added relate to the multiplier and multiplicand? Tips for Learning Multiplication Tables [08/13/1998] I have great difficulty with my 4, 6, 7, 8, and 9 times tables... Using Parentheses [11/16/1998] Can you explain how to use parentheses to tell the order of operations? What is 4/5 x 10? [2/10/1995] What is the answer to this fraction? Please explain. What is an exponent? [8/8/1996] Can you explain what an exponent is? Working with Integers [01/12/1999] Could you explain how to divide, multiply, add, and subtract integers? 3/4 of _____ Is 90 in Three Ways [03/24/2010] In a multiplication problem like "Three-quarters of _____ is ninety," how do you fill-in- the-blank with the factor that satisfies the equality? Doctor Ian presents three different methods: guess-and-improve; the equivalency between multiplication and division; and multiplying through by a reciprocal. Adding a Zero When Multiplying a Decimal [06/21/2001] I don't understand why you add a zero when multiplying decimals. Adding Tax and Tip [07/19/1998] In pricing our hotel luncheons, we charge a base price plus a 6.8% tax and a 20% service charge. How would I find the total in one step? Additive Identity and Other Properties [01/03/1999] Can you explain the identity of zero and the commutative and multiplicative properties? Why are they special? Page:  1  2  3  4  5 [next>]

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