Math Out Loud!

[audio:http://mathoutloud.edublogs.org/files/2008/10/composite-number.mp3]

Today on math out loud we’ll focus on the word story of composite numbers, c-o-m-p-o-s-i-t-e n-u-m-b-e-r-s. The definition of composite number is a number that has more than two factors. We first started to use the word composite numbers in 1772. An example of a composite number is 8. It’s a composite number because it has four factors, 1, 2, 4, and 8. A non-example is prime numbers like 3, 5, 7, 11, 13, 17 and 19. These numbers only have 2 factors, the number itself and 1. If you don’t know what factors are, check our our other word story! We’re the math masters with the word story of composite numbers on Math Out Loud!!!!

[audio:http://mathoutloud.edublogs.org/files/2008/10/distributive_property.mp3]

Today on Math Out Loud we’ll focus on the words distributive property, d-i-s-t-r-i-b-u-t-i-v-e p-r-o-p-e-r-t-y. You can use the distributive property when you want to break down a problem to make it easier. It is useful when there is a 2-digit or larger number that you are trying to multiply. To use the distributive property, you break up the 2-digit or larger number and then multiply. For example, if you have the problem 32 x 4, break up the 32 into 30 + 2. Then we multiply 30 x 4 and 2 x 4. Then you add the products. So you add 120 plus 8 to get 128. A non-example would be 9 x 8 because breaking it up doesn’t really make the math easier to do in our head. We’re the Math Masters with the word story of distributive property on Math Out Loud.

[audio:http://mathoutloud.edublogs.org/files/2008/10/variable.mp3]

Today on Math Out Loud we’ll focus on the word variable, v-a-r-i-a-b-l-e. When we first learned about letters when we were young, they were used for reading, writing and spelling. Now that we are older we know that letters can be used in math, too! A variable is aletter in a mathematical expression such as n, x, s, b, or any other letter. The variables are the letters. Numbers are not variables. A variable is a letter that represents aquantity that can change. In an algebraic equation such as x + 3 = 8, the variable is x. The numbers 3 and 8 in that equation are not variables. They are called constants. We’re the Math Masters with the word story of variables on Math Out Loud.

[audio:http://mathoutloud.edublogs.org/files/2008/10/compatible_numbers.mp3]

Today on Math Out Loud, we’ll focus on the words Compatible numbers, c-o-m-p-a-t-i-b-l-e n-u-m-b-e-r-s. When two people are compatible they both get along like friends. When numbers are compatible, they are friendly also. Compatible numbers are numbers that are easy to work with mentally. They are numbers that are close to the numbers that are given in the problem. We use compatible numbers when estimating. An example of using compatible numbers is when solving 15 divided by 4. We could change the 4 to a 5 and then we coudl work the problem mentally. A non-example is when we work out the same division problem even with a remainder.We’re the Math Masters with the word story of compatible numbers on Math Out Loud.

[audio:http://mathoutloud.edublogs.org/files/2008/10/sequence.mp3]

Today on Math Out Loud we’ll focus on the word sequence, s-e-q-u-e-n-c-e. The first time the word sequence was used in a mathematical context was in 1882 in the American Journal of Mathematics by James Joseph Selvester. A sequence is a set of numbers arranged in a special order or pattern. An example of sequence is an organized list like naming the numbers in order. A non-example is an unorganized list like the numbers being all mixed up all over the place. We’re the Math Masters with the word story of sequence on Math Out Loud.

[audio:http://mathoutloud.edublogs.org/files//var/www/edublogs/public_html/wp-content/blogs.dir/dist/d/184403/files//2008/10/evaluate.mp3]

Today on Math Out Loud, we’ll focus on the word evaluate, e-v-a-l-u-a-t-e. The word evaluate is used in science and in everyday life but we’ll focus on the way we use it in math. The first time the word evaluate was used in a mathematical context was in 1842 in a Physics book by William Grove. Evaluate means to find the value of a numeric or algebraic expression. In other words, it means to solve or work out a value. An example of evaluate is 4 + 3 = 7 or 105 + 5 = 110. A non-example is giving up and not working out the problem. We’re the Math Masters with the word story of evaluate on Math Out Loud!