Why does a Negative number times a Negative Number Equal a Positive Number?

Have you ever wondered why a negative number times a negative number equals a positive number? As my mathphobic daughter would say, "No, Mom. Math is something I never think about!" Well, for all of us who tend to be left brained people, the question can be answered by using a pattern. After all, all math is based on patterns!

Let's examine 4 x -2 which means four sets of -2. Using the number line above, start at zero and move left by twos, four times. Voila! The answer is -8. Locate -8 on the number line above.

Now try 3 x -2. Again, begin at zero on the number line, but this time move left by twos, three times. Ta-dah! We arrive at -6. Therefore, 3 x -2 = -6.

On the left is what the mathematical sequence looks like. Moving down the sequence, observe that the farthest left hand column decreases by one each time, while the -2 remains constant. Simultaneously, the right hand answer column increases by 2 each time. Therefore, based on this mathematical pattern, we can conclude that a negative number times a negative number equals a positive number!!!!

Isn't Mathematics Amazing?

Using Math Riddles to Reduce Fractions, Recognize Equivalent Fractions, Identify Basic Percents

Do you need something besides a “drill and kill” activity to practice fractions and/or percents? This fraction riddle bundle is my newest bundled resource. It is a 33 page resource that is a fun and engaging way to utilize math concepts while keeping the students actively involved. 

Specific words are provided. The students are instructed to figure out the correct fractional part of each particular word. (Example: The first ½ of WENT would be WE. Notice that WE is also 2/4 or 50% of WENT.) If each fractional part is correctly identified, when the students write the fractional parts on the lines provided, a new word is created. Each group of new words becomes a riddle or the answer to a riddle.

It is important that students understand that a fraction and a percent represent the same thing; so, in the Snow Riddles handout, 25%, 50%, 75% and 100% are introduced.

 In March Riddles, specific questions are asked to acquaint the students with fun facts about the month of March. April Riddles introduces the students to several interesting historical facts that occurred during this month.

For each month, there are between 7-11 word fraction riddles; so, there are numerous ways to practice recognizing fractional parts, understanding equivalent fractions, identifying basic percents (25%, 50%, 75% 100%), and reducing fractions to lowest terms.

Instead of completing all of the monthly riddles in one day, the puzzles may be divided up and used as a focus activity, when a student finishes early, or when there is a short amount of time left before the next class or activity. An individual puzzle may be given each day, or the riddles can be interspersed throughout the week or month. Answers are included at the end of each month’s activities. The complete resource features six months (January, February, March, April, October, December) and contains a total of 49 fraction riddles.

If you prefer, each month of fraction riddles may be purchased separately; however, this resource bundles all six months for a discounted price. Just click the title under the cover page shown above, and download the preview to take a quick look at this new item.