Valentine Mailbox Design - Part 1

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SWBAT set criteria for a new improved Valentine Boxes and create individual blueprints to use when they build their Valentine Boxes in the next lesson.

Big Idea

Students explore the steps of an engineer when they design, build and evaluate individual Valentine mailbox designs.

NGSS Connections and Lesson Preparation

30 minutes

NGSS Standards

K-2-ETS1-1    Ask questions, make observations, and gather information about a situation people want to change to define a simple problem that can be solved through the development of a new or improved object or tool.

Students look at the 'usual bag Valentine mailbox' and make observations to define the problem with the 'bag mailbox'.

K-2-ETS1-2    Develop a simple sketch, drawing, or physical model to illustrate how the shape of an object helps it function as needed to solve a given problem.

Students create a diagram for a 'new and improved Valentine mailbox' to improve its functionality.

Science Practices

- Defining Problems (SP 1)

Students make observations to help define the flaws with a paper bag Valentine mailbox.

 - Developing and Using Models (SP 2)

Student create a diagram to address the design flaws of a paper bag Valentine mailbox.

Cross-cutting Concepts - Appendix G

- Structure and Function (XC 6)

Students consider how the structure of the paper bag and the new and improved Valentine mailbox's structure assists to varying degrees with its function.

Lesson Preparation

have envelopes and paper bag mailbox ready to show the merits and drawback to this type of mailbox

send out a Letter to Families at least two weeks ahead requesting boxes to be used for the mailbox


diagram paper (I used 9 x 18 in manilla paper, to give the kiddos lots of room to create and label their design)

material for making mailbox (students will not be using this material this week, but the items should be available/listed so they can refer to it while making their diagram)

building material: glue, masking tape, rubber bands, yarn, pipe cleaners

material to add base weight to the mailbox


Question for the Day

5 minutes

When students return from lunch, we meet on the rug to read our 'science question for the day'. I have established this routine with the kiddos to keep transition time short and effective and redirect student's attention back to content while allowing time for focused peer interaction. The 'question of the day' provides an opportunity for students to consider today's topic before the lesson has officially begun.

Question of the Day: What is a mailbox?

After students turn and share with each other, I call on volunteers to answer the question. I write student responses on the board.

I will refer to their answers to the question of the day, as they begin to decide the elements for their Valentine mailboxes.

Mailbox Criteria and Constraints

15 minutes

"I have asked you all to think about mailboxes because ... Right, Valentines is just around the corner and you all will be passing out Valentines."

"In previous years students have decorated bags to use as their Valentine mailbox, but let me show you what happens with this type of mailbox."

I demonstrate the following flaws with the 'bag mailbox':

    the bag falls after more mail is placed in the bag

    the name isn't visible so the mailer isn't sure who they are mailing to

    owner tries to pick up the bag, but mail falls out or it is difficult to carry

I ask students to summarize their observations about what did not work well with the bag. These are listed on the board, under the heading: Problem with 'Bag Mailbox'.

Next I ask students if there is anything about the 'bag mailbox' that works.

I may act out what does work well with the mailbox to help scaffold students' thinking.

I hope students point out:

     easy to place the mail in the bag and take the mail out

These observations are also noted on the board, under the heading: Valentine Mailbox Criteria.

I point to the word 'criteria', "When you think of the mailbox criteria, I want you to think about what your mailbox should include to improve on the 'bag mailbox'. You will use the 'criteria' as your checklist for what your mailbox should be able to do. The mailbox criteria are your parameters that you will consider when building your mailbox."

"Let's look back what the 'bag mailbox' did not do well so that we can think about what we want our new and improved 'Valentine Mailboxes' to be able to do."

"You noticed that the bag fell over, what should our new and improved 'Valentine Mailboxes'  be able to do? Yes, we could say it with a negative, 'not' ..., but is there a way we could describe what our mailbox should be able to do?"

"O.K. the new and improved 'Valentine Mailboxes' will stay standing, upright, with 24 envelopes and assorted small objects placed inside."

Through scaffolding, I help students devise a way to measure how well their mailbox meets each criteria. In this example, students will be able to test that the mailbox will hold 24 cards without falling over.

After our discussion is complete the following 'new and improved 'Valentine Mailboxes' criteria is listed:

mail drops into the mailbox, leaving the opening clear for new mail

mail can be taken out of the mailbox with your hand

the mailbox stays in its original position with 24 envelopes and assorted objects placed inside

the mailbox can be carried with one hand, without any mail falling out

owner's name is on the box and easy to read

May want to include a 'parcel slot' for items that do not fit in the card slot.

"This is your criteria, parameters for the mailbox you will design. Is there anything else you can think of that our mailboxes should have?"

I want to include student ideas and allow time for the class to discuss the merits of any new criteria pieces.

"Alright we all agree that for your mailbox to be a successful design, it must have this criteria?" I point to the criteria list the students have created.

"Your designs will have certain constraints or limitations. For example, we do not have all types of materials or resources to use to build your mailboxes. So, your constraints for how you will build your new and improved 'Valentine Mailboxes' will be limited to the resources that are available for you to use."

I show them the bin with the building supplies  (tape, glue, pipeclearners and yarn). I start a new list on the board next to 'Mailbox Criteria' called 'Mailbox Constraints'. Through a guided discussion the following constraints are listed:

the mailboxes may only be built with material provided

the base of the mailbox must be able to sit on your side of the desk 

the mailbox cannot be attached to your desk

Mailbox Design

25 minutes

"You will use the remaining time to create a diagram of your mailbox to show how you will address the criteria. Your diagrams will help map out what you will build and the material you will want to use for your mailbox."

"You will need to think about your mailbox design so that it can meet the criteria. For example, What kind of shape would help my mailbox stand up, and not fall over?"

I use student suggestions to model how to label the diagram to show how it meets the criteria.

What parts of the mailbox help it to not fall over? As volunteers share with me, I note these on my diagram. Such as 'the wide base or bottom of the box will keep it from falling over, or the cardboard will keep the sides straight'.

Students may have other ideas, and I will note these too. My goal is to get students to start to think about design and function and the physics behind it, not to necessarily teach proportion ect.

One student said the box won't fall over because the cards will go to the bottom and add weight!

Next I show students how to label the slot opening and write the measurements for the length and width. I explain that diagrams should include the measurements so another engineer could follow  their plan and make a similar mailbox.

I stress that this is not the time to decorate their mailbox diagram.

I pass out paper students will use for their diagrams and walk around to ask questions about the students' designs.

The kiddos were curious to see what their neighbors were doing and ready to suggest ideas.

I place building material samples at each table for students to handle as they work out their mailbox diagram.   

As students finish, they check their diagrams with the criteria list on the board and share with a partner. Afterwards, they hand their diagrams to me. I check diagrams for clarity, that materials are listed and the 'criteria' has been met, as shown with their labels.



5 minutes

We discuss what was tricky about making the diagrams and what was easy. I place a couple of completed or nearly completed diagrams under the document camera and encourage the engineer to explain his diagram.

Before students are dismissed, I remind them that their diagrams need to be completed and approved before they can build. Students may choose to take home their diagram to complete. Otherwise I will plan time in the week for students to complete their design.

If students selected their boxes, remind them to write their name on the bottom of the box.