Lesson

=Lesson/Activity/Assessment=


 * Now that arrays, factoring, and number puzzles have been practiced students can participate in an activity that will involve all three concepts. The idea of the lesson is to incorporate and use all three concepts into one lesson to assess learning from the previous activities. The number puzzles were only briefly touched on just so that students know how to use and complete puzzles for the lesson that can now be used.**


 * Materials:** Smart board or projector, graph paper

4.OA.2. Multiply or divide to solve word problems involving multiplicative comparison, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem, distinguishing multiplicative comparison from additive comparison.1 (Students will connect this standard by using arrays to represent a product of an equation as well as differentiate between multiplication and addition. The focus here is not so much on the arrays themselves but on the use of them to master the concept).
 * Common Core Standards Addressed:**

4.OA.3. Solve multistep word problems posed with whole numbers and having whole-number answers using the four operations, including problems in which remainders must be interpreted. Represent these problems using equations with a letter standing for the unknown quantity. Assess the reasonableness of answers using mental computation and estimation strategies including rounding.

4.OA.4. Find all factor pairs for a whole number in the range 1–100. Recognize that a whole number is a multiple of each of its factors. Determine whether a given whole number in the range 1–100 is a multiple of a given one-digit number. Determine whether a given whole number in the range 1–100 is prime or composite.


 * Use a few of the online games to review concepts of arrays and have students create a few factor trees as well.**


 * After reviewing factors and arrays students will be put into groups of two or three and each given a sheet of graph paper along with a list of 8-10 number puzzles to solve. They will work in their groups but each turn in their own copies. Each puzzle will lead to the creation of an array on the graph paper. The number puzzles should be created to help the students create an array without too much difficulty. For example 1-The length of this array is a multiple of 3 and 5. 2-The length of this array is less than 30. 3-The height of this array is a prime number. 4-The height can be found by factoring the number 20. 5-The height is the lowest factor greater than 1.**
 * The array should end up with a length of 15 and a height of 2. Do the first one on the projector or smart board to demonstrate and answer questions.**
 * After students have completed all of the number puzzles and illustrated the arrays on the graph paper ask them to write an equation that represents the number of squares using both addition and multiplication. Have the students do this on a separate sheet of paper. For this particular example their answer should look like this:**
 * Number Puzzle 1 = 15x2 or 15+15**
 * Students will turn in their own copies of the graph paper with each array illustrated and the separate paper with the equations.**


 * You have also just set up for future lessons for area.**