Transcript Document
Elmer Explains Arrays & Area The “doggie version” of mathematics. By: Ian Wright & Elmer Pug A little about Me… Well hello there. My name is Elmer Ping Pong Wright Lyon and I am going to explain two math words to you today in my own doggie way. Let’s start out with some facts you already know… When we multiply, this means a number is added to itself a number of times. For example: 3 x 4 = 12 + + =12 Elmer looks sleepy… Zzzz… Elmer! You’re falling asleep on the job! Oops! Sorry folks, back to business! On to the fun stuff! Let’s learn a new math word, but this time we will use yummy treats instead of boring dots so I don’t fall asleep! Our new word is… array. An array is a set of objects or numbers arranged in order, often in rows and columns. Here is an array for the number 6: This array is called 1 by 6 Can you guess why it has this name before I eat these delicious bacon heart treats? and 6 columns There is 1 row Therefore this array is 1 by 6 or 1 row by 6 columns. Mmm… an array of bacon treats. What would you call this array? A delicious snack? This array is 6 by 1 because… There are 6 rows 6 rows by 1 column Hey! Doesn’t 6 x 1 = 6? and 1 column Elmer is right! 6 x 1= 6 1 by 6 AND 6 by 1 are BOTH arrays for the number 6 Elmer gets a treat and if you got the right answer too, pat yourself on the back Let’s think of another array we can make with the number 6… ? First, let’s think about what numbers we multiply to get 6… 1x6=6 6x1=6 2x3=6 3x2=6 Is that it? Yes! So let’s try another array of 6. How would you draw 2 by 3 or 3 by 2? Here is my doggie version of 2 by 3 There are 2 rows and 3 columns I still have 6 total heart bacon treats. Hooray for array! Are you ready to help Elmer with some bigger arrays? HERE IS HOW YOU CAN HELP ELMER: How many arrays of 12 are there? Draw them out and label them on your piece of scratch paper. These are my gingerbread man treats. Did I put them in the correct arrays? 1 by 12 Is there 1 row and 12 columns? 12 by 1 Are there 12 rows and 1 column? Elmer is correct! Hooray! But there are 4 more arrays of 12. Elmer, keep going! 1 by 12 Is there 1 row and 12 columns? 12 by 1 Are there 12 rows and 1 column? What do you think about these arrays Elmer created? 2 by 6 Are there 2 rows and 6 columns? 6 by 2 Are there 6 rows and 2 columns? Hooray! Elmer knows arrays! Do you? 2 by 6 Are there 2 rows and 6 columns? 6 by 2 Are there 6 rows and 2 columns? Last, but not least, check Elmer’s work… 3 by 4 Are there 3 rows and 4 columns? 4 by 3 Are there 4 rows and 3 columns? Elmer ROCKS! He got all arrays of 12 correct! 3 by 4 Are there 3 rows and 4 columns? 4 by 3 Are there 4 rows and 3 columns? I am SO doggone smart! Now that you know array, Area will be a piece of cake. Our new word is… area. Area is the size a surface takes up The area for parallelograms, such as rectangles and squares, is length x height: clue: This array is called 1 by 6. Can you guess the area of this array before I eat these delicious bacon heart treats? Length (l) = 6 Height (h) = 1 Therefore the area of these treats is 6 x 1 = 6 square units. That is l x h. An area of bacon treats. Delicious! I have SO many treats I don’t have time to eat all of them right now! tip: Area is made up of square units. Help me figure out the area of the dirt I need to dig up in the backyard in order to bury all of my treats. Length (l) = 6 Height (h) = 3 Array = 3 by 6 Area = 18 square units Now we both know area and array! HOORAY! I am SO happy that we could learn about arrays and area together! QuickTime™ and a Motion JPEG OpenDML decompressor are needed to see this picture. Just for Fun… *Watch Elmer do a few of the tricks he already knew… Woof! Woof! Woof! Woof! The End! Woof! Woof! Woof! Woof! TEKS used in digital book 4th Grade Math: (4.4) Number, operation, and quantitative reasoning. The student multiplies and divides to solve meaningful problems involving whole numbers. (A) Model factors and products using arrays and area models; (B) Represent multiplication and division situations in picture, word, and number form; (C) Recall and apply multiplication facts 12 x 12; (D) Use multiplication to solve problems (no more than two digits times two digits without technology) *I did not have students use division as of yet, but could switch up later in the year to include division.