2. Lucky number 21 By Fredrik Meyer Note: you have to press spacebar or click The mouse to continue to every slide. You do not need to click for this one, it is automatic.

3. Lucky number 21 Now, I’ll tell what this number is good for and why I picked it I picked the number 21 because I have a song in my head and the song goes C’est la vie always 21.

4. Lucky number 21 A few facts about this number is: It is a composite and an odd number. All of the factors are 1,3,7 and 21. The proper factors of 21 is 1,3 and 7. The factor pairs are 3 and 7, 1 and 21. The number 21 is a deficient number because all of it’s proper factors add up to be less than 21.

5. Lucky number 21 Factor tree of 21: 21 37x The prime factorization of 21 Is 3x7.

6. Lucky number 21 A few connections from that number in real life is that we use it in math class: We have to spend $21.00 on food and other things. A popular card game is called 21, or “black jack”, this game can be played in casinos around the world. Also as I mentioned in the beginning, there are songs that contain the number 21.

7. Lucky number 21 The number 21 is an OK move to begin with for both games (product and factor game). In the product game you should always start in the middle so that you have more ways to go than only being in the corner, but 21 starts pretty close to the middle so it is an OK move. 21 in the factor game is OK because the other person gets about half as much as you get.

8. Lucky number 21 Thank you for listening! Press space to continue to Vocab.

9. Lucky number 21 Glossary: Factor = One of two or more whole numbers multiplies to get a product. Composite = A number with 3 or more factors. Odd = A number that is not a multiple of 2. Multiple = The product of a given whole number and another whole number. Proper factor = All the factors of a number, except the number itself. Factor pair = Two whole numbers that are multiplied to get a product.

10. Lucky number 21 Glossary: Deficient = A number for which the sum of all it’s proper factors is less than the number itself. Perfect = A number for which the sum of all it’s proper factors is the number itself. Near-Perfect = A number for which the sum of all its proper factors is one less than the number. End of Slideshow