3rd-5th Grade Math Calculator Activity

Number Thief! 

Grade Level

The grade level that I chose for this calculator activity was third to fifth grade.  It could be adapted for a variety of grades by lowering the quantity and/or magnitude of numbers students are required to find, limiting the operations to addition and subtracting, or allowing the students to use more number buttons and having fewer “stolen buttons.”

Mathematics Topics

This activity covers a wide range of mathematics topics.  The most obvious is calculator fluency, or the ability to effectively use a calculator in a meaningful way to accomplish mathematical tasks.  Students will also need the ability to perform basic operations (addition, subtraction, multiplication, and division) in order to get to a certain number.  Student will need to apply the properties of these operations (i.e. associative, communicative, etc. properties) while carry out this activity.  This activity will also be used to introduce or reinforce the concept of order of operations.

Common Core State Standards

3^rd grade:     3.OA.1. Interpret products of whole numbers, e.g., interpret 5 × 7 as the total number of objects in 5 groups of 7 objects each. For example, describe a context in which a total number of objects can be expressed as 5 × 7.

3.OA.2. Interpret whole-number quotients of whole numbers, e.g., interpret 56 ÷ 8 as the number of objects in each share when 56 objects are partitioned equally into 8 shares, or as a number of shares when 56 objects are partitioned into equal shares of 8 objects each. For example, describe a context in which a number of shares or a number of groups can be expressed as 56 ÷ 8.

3.OA.4. Determine the unknown whole number in a multiplication or division equation relating three whole numbers. For example, determine the unknown number that makes the equation true in each of the equations 8 × ? = 48, 5 = �� ÷ 3, 6 × 6 = ?.

3.OA.5. Apply properties of operations as strategies to multiply and divide.2 Examples: If 6 × 4 = 24 is known, then 4 × 6 = 24 is also known. (Commutative property of multiplication.) 3 × 5 × 2 can be found by 3 × 5 = 15, then 15 × 2 = 30, or by 5 × 2 = 10, then 3 × 10 = 30. (Associative property of multiplication.) Knowing that 8 × 5 = 40 and 8 × 2 = 16, one can find 8 × 7 as 8 × (5 + 2) = (8 × 5) + (8 × 2) = 40 + 16 = 56. (Distributive property.)

3.OA.6. Understand division as an unknown-factor problem. For example, find

32 ÷ 8 by finding the number that makes 32 when multiplied by 8.

5^th grade:     5.OA.2. Write simple expressions that record calculations with numbers, and interpret numerical expressions without evaluating them. For example, express the calculation “add 8 and 7, then multiply by 2” as 2 × (8 + 7). Recognize that 3 × (18932 + 921) is three times as large as 18932 + 921, without having to calculate the indicated sum or product.

Instructions

A thief has come to our classroom and has stolen number buttons from our calculators!  In order to get all of our buttons back, we need to follow the instructions the number thief gave us on this note he left behind:

Dear 5th graders,         I have stolen your numbers!  The only way to get them back is to prove that you can still do math with only two numbers.  I’ll give your numbers back only after you find each number from 1 to 20 using only these buttons: 2  3  +  -  x  /  = You must use multiplication for at least 5 numbers and division for at least 3 numbers.  If you can, find more than one way to get to each number.  Fill out the record sheets in the folder so that I know that you followed my instructions.                                          Sincerely,                                                 The Number Thief

Alright 5^th grade, we better get working!  Don’t forget to record your answers on the record sheets in the folder.  Find one solution for each number, then, if you have time or if you figure out another solution record it on the second line for that number.  Remember, you can only use the numbers 2 and 3 to find all of the other numbers.  Good luck!

Related Materials Needed

            All the materials for this calculator learning center will be included in a folder and placed on a table for the students (see attached folder).  The instructions provided above will be printed on a 5” by 7” notecard.  In this folder there will also be enough record sheets for each student or student pair.  There will be enough calculators for each student or student pair.  The teacher may wish to place temporary stickers over the keys that the Number Thief has “stolen” to remind students that they cannot use these buttons on the calculator.  Pencils and scratch paper will also be placed at this learning center.

Bibliography

Calculator Puzzle Card . (n.d.). Retrieved October 5, 2011, from Super-Gran Puzzle-Maker: http://supergran-puzzlemaker.net/T31.htm  (see attached)

The Standards: Mathematics. (2011). Retrieved October 6, 2011, from Common Core State Standards Initiative: http://www.corestandards.org/the-standards/mathematics

"Thief" image from Microsoft office 2007 clipart.

NUMBER THIEF RECORD SHEET!

Number	How I Got This Number (Which Buttons I Pushed)
ex. 24	2 x 2 = 4 x 2 = 8 x 3 = 24
	2 + 3= 5 x 2 = 10 x 2 = 20 + 2 = 22 + 2 = 24
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Bonus!	If you have time, try these bonus numbers for an extra challenge!
47
53
117