Decomposing the Number 5: A Comprehensive Mathematical Study Guide

Core Concepts of Decomposing

  • Definition of Decomposing: Decomosing is described in the lesson as the process of "breaking stuff down" or taking a whole number and breaking it into "part, part."

  • Key Characteristics:     * Decomposed parts do not necessarily consist of the same number.     * The parts are distinct from the starting whole but must add back up to that whole.

  • Class Chant and Mnemonics:     * "Decompose, decompose, break it on down, break it on down. Decompose, decompose, break it on down, break it on down."     * "Start with a whole, part, part. Start with a whole, part, part."

  • Affirmations and Mirroring:     * "I can take the whole number 55 and break it into part, part."     * "I can use objects to show the part, part."

Mathematical Patterns and Predictions

  • Review of Previous Numbers: The class historically reviewed numbers 11, 22, 33, and 44.     * For the number 11: There is only 11 way to decompose it.     * For the number 22: There are 22 ways to decompose it (using specific finger gestures).     * For the number 33: There are 44 ways to decompose it.

  • Elle’s Pattern Prediction: Student Elle identified a numerical pattern in decomposition possibilities:     * The number of ways to decompose a number is usually the number itself plus 11.     * Elle predicted that for the number 55, there would be exactly 66 ways to decompose it.

  • Logical Constraints: Mathematicians look for patterns. For any whole number XX, the parts must be lower than XX. For example, if the whole is 55, all parts must be less than or equal to 55.

The Movie Theater Simulation (Whole=5Whole = 5)

  • Scenario: Five girls (Isabella, Molly, Elle, Tyler, and Faith) have movie passes and enter a theater with five chairs. The theater is divided into two parts (left side and right side).

  • Sequential Decompositions of 5:     1. Stage 1: 00 people on the left, 55 people on the right (00 and 55).     2. Stage 2: Molly moves to the left. Now there is 11 person on the left, 44 on the right (11 and 44).     3. Stage 3: Isabella feels the chair "is not right" and moves. Now there are 22 people on the left, 33 on the right (22 and 33).     4. Stage 4: Tyler moves because there is "gum on the seat." Now there are 33 people on the left, 22 on the right (33 and 22).     5. Stage 5: Faith moves because her seat is "too sticky." Now there are 44 people on the left, 11 on the right (44 and 11).     6. Stage 6: Elle moves to talk with her friends during a "really good part" of the movie. Now there are 55 people on the left, 00 on the right (55 and 00).

  • Conclusion: Elle’s prediction was correct. There are 66 ways to decompose 55. The resulting pattern is:     * Left side: 0,1,2,3,4,50, 1, 2, 3, 4, 5     * Right side: 5,4,3,2,1,05, 4, 3, 2, 1, 0

Storytelling and the "Quackulator"

  • Book Title: Little Quack by Lauren Thompson.

  • Materials: Students use a "Quackulator" (a tower of 55 linking cubes) and a story mat to track the movement of ducklings.

  • Characters: Mama Duck and her five ducklings: Widdle, Waddle, Piddle, Puddle, and Little Quack.

  • Narrative Decomposition Steps:     * The Nest: Initially, all 55 ducklings are in the nest (55 in nest, 00 in pond).     * Widdle: Jumps in first. Result: 44 in nest, 11 in pond.     * Waddle: Jumps in next. Result: 33 in nest, 22 in pond.     * Piddle: Feels brave and jumps. Result: 22 in nest, 33 in pond.     * Puddle: Leaps in. Result: 11 in nest, 44 in pond.     * Little Quack: Eventually plunges in. Result: 00 in nest, 55 in pond.

  • Supplemental Song: "Five Little Ducks Went Out One Day."     * Process: Mama duck calls, and one by one, ducklings return to the water.     * Goal: Tracking parts as they move from "over the hills" to the pond.

The Grocery Store Problem

  • Problem Statement: Ms. Stafford and her mother went shopping and bought 55 items. They have 22 grocery sacks. Students must determine how many ways the items can be distributed between the two bags.

  • Student Work Procedures:     * Use cubes to represent grocery items.     * Use a recording sheet with two circles (representing the sacks) to draw the items (dots or circles).     * Record combinations of parts that equal the whole of 55.

  • Partner Observations:     * Maddie and Riley: Found a way where the mother has 22 and the daughter has 33. They also found 44 and 11.     * Jordan and Tyler: Explored "all for Ms. Stafford (55) and none for mom (00)," and then vice-versa.     * Elle and Dalton: Logged 33 on one side and 22 on the other.

Learning Centers and Rotations

Students rotate through specialized stations to practice decomposing 55:

  • Jewels Table: Using colored beads hooked together.     * Faith used 55 blue beads and 00 of other colors.     * Kennedy used 33 black beads and 22 green beads.

  • Number Bracelets: Sliding beads on a pipe cleaner to show part-part relationships.     * Brantley showed 22 and 33, then 33 and 22.     * Elle showed 11 and 44.

  • Two-Sided Beans Table: Tossing beans with two different colored sides (red and white).     * Riley recorded 22 white and 33 red.     * Tyler recorded 55 red and 00 white.

  • Small Group (Spider Web Activity):     * Metaphor: A spider web and an "egg sac."     * Action: Spiders crawl from the egg sac onto the web.     * 55 in sac, 00 on web.     * 44 in sac, 11 on web.     * 33 in sac, 22 on web.     * 22 in sac, 33 on web.     * 11 in sac, 44 on web.     * 00 in sac, 55 on web (Zero means "none," "nothing," or "not any").

Questions & Discussion

  • Question: "Joseph, if you'll raise your hand if you can remember what we've been talking about this week?"

  • Response: "Decomposing."

  • Question: "Faith, what did you and Brantley talk about when you were talking about decomposing?"

  • Response: "We were talking about start with a whole, part, part."

  • Question: "Tyler, what did you and Jordan talk about?"

  • Response: "They're not the same numbers… they were different parts."

  • Question: "Isabella and Molly, what did you talk about?"

  • Response: "We talked about breaking stuff down by putting it in parts and breaking it."

  • Question: "What did we find out [about the number three] Elle?"

  • Response: "That we can decompose… it's kind of like a pattern… one's two, and two's three, and three's four, and four's five. And I think five is going to be six."

  • Question: "What is my whole that I'm starting with [at the movie theater]?"

  • Response: "Five."

  • Question: "What do we know zero means Logan?"

  • Response: "It means nothing."

  • Question: "What is that that good mathematicians are always looking for in numbers?"

  • Response: "A pattern."

  • Question [to Emma]: "How many is in the water Miss Emma?"

  • Response: "Four."

  • Question [to Jordan]: "Jordan, how many do you have in the water now?"

  • Response: "Two… Oh, another one just came back… Three."

  • Question: "Why do you call it a 'handy dandy' [clipboard]?"

  • Response: "Cause it's right here. It's close and handy. It's got everything we need right there."


The observation video highlights the importance of hands-on learning, which engages students more deeply in the subject matter. It showcases how visual aids, such as diagrams and objects, enhance understanding by making abstract concepts more tangible. Additionally, the video demonstrates the effectiveness of peer collaboration, where students learn from each other through discussion and teamwork. In an elementary classroom, these practices can be applied by incorporating interactive activities and group projects that encourage student participation and deepen comprehension of the material.