Sum of Products
Date: 11/01/1999 at 12:38:16 From: Tasha Subject: Products of math When in a word problem it asks for the sum of a product, is the product the answer of all of the sums added together?
Date: 11/14/1999 at 19:54:44 From: Doctor TWE Subject: Re: Products of math Hi Tasha - thanks for writing to Dr. Math. You ask a good question. In math, when we use the word "sum," we mean add the numbers. When we use the word "product," we mean multiply the numbers. So the "sum of the products" means we want to add (sum) the results of numbers being multiplied (products). Let me give you an example. Suppose we have 3 nickels, 4 dimes and 2 quarters. To find the value of the nickels, we multiply (find the product of) 3 * 5 cents = 15 cents. To find the value of the dimes, we find the product of 4 * 10 cents = 40 cents. Likewise, to find the value of the quarters, we multiply 2 * 25 cents = 50 cents. To find the total value of all the coins, we add up (sum) 15 cents + 40 cents + 50 cents = 105 cents, or $1.05. Here, we added up ("took the sum of") all the results of the multiplications ("the products.") I hope this example helps clear it up. Write back if you have any more questions! - Doctor TWE, The Math Forum http://mathforum.org/dr.math/
Search the Dr. Math Library:
Ask Dr. MathTM
© 1994-2013 The Math Forum