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Grant Budget Laptop Calculator

Run the Grant Budget Laptop Calculator MicroSim fullscreen

About This MicroSim

The arithmetic is a division. The value is doing it before the money is spent.

Platform is the biggest lever. A $3,000 grant buys twelve Chromebooks or three MacBooks. Whether that matters depends on what the club actually does — web-based work runs fine on a Chromebook, and video editing does not — but deciding that after the purchase order is the expensive way round.

The leftover is the number people skip. Every combination leaves something, and the tool shows it because a leftover is real money that quietly evaporates unless it is assigned. $300 left from a $3,000 grant is a robot kit, a year of consumables, or the spare device you will need when one gets dropped in November. Write it into the application, not into next year's regret.

Buy a spare if you can. The tool flags it when the fleet exceeds the student count, because the day a device fails is the day a student has nothing to work on. One spare in twelve is cheap insurance.

One honest caveat the sim states and does not model: the prices are list prices. Tax, shipping, and any device management licence typically add ten to fifteen percent, so a grant that divides exactly here will not divide exactly at the checkout.

How to Use

  • Drag Grant amount and watch the device count and coverage change together.
  • Switch Platform without touching the grant. The same money buys a very different fleet.
  • Choose Custom price to enter a real quote — refurbished machines and education pricing are both worth entering.
  • Set Students to your actual club size and look for the point where coverage tips over.
  • Reset to defaults returns to $3,000, Chromebooks, and 12 students.

Lesson Plan

Bloom level: Apply (L3) -- calculate

Learning objective: Given a grant amount and a chosen device platform, the learner calculates how many laptops the grant can purchase, how much budget remains, and how many students the resulting fleet can serve one-to-one.

Before the sim (5 min). Ask how many laptops a $3,000 grant buys. Somebody will say a number without asking which laptop, and that is the point.

With the sim (10 min). Run each platform at the same grant. Then work backwards: what grant would you need to cover your club on each platform? That number is what goes in the application.

After the sim (20 min). Get real quotes, including tax and shipping, and re-run it with Custom price. The gap between the list price and the real one is usually enough to change the answer by a device.

Check for understanding. Ask: "Your grant buys eleven devices for twelve students, with $80 left. What do you do?" Ask for a slightly larger grant, buy eleven and pair one session activity, or find a cheaper eleventh — but not "hope". Naming which trade you are making is the skill.

Embedding This MicroSim

Paste this into any page of the book, adjusting the relative path to docs/sims/ for the page's depth:

<iframe src="../../sims/grant-budget-laptop-calculator/main.html" width="100%" height="502" scrolling="no"></iframe>

Specification

The full specification below is extracted from Chapter 22: Purchasing and Configuring Club Devices.

Type: microsim
**sim-id:** grant-budget-laptop-calculator<br/>
**Library:** p5.js<br/>
**Status:** Specified
**Template:** https://github.com/dmccreary/economics-course/tree/main/docs/sims/budget-builder

Purpose: Let a club leader explore how a grant budget converts into a device count under each platform, and see the leftover-budget and per-student-coverage consequences of that choice before committing real money.

Bloom Taxonomy: Apply (L3)
Bloom Taxonomy Verb: calculate

Learning objective: Given a grant amount and a chosen device platform, the learner calculates how many laptops the grant can purchase, how much budget remains, and how many students the resulting fleet can serve one-to-one.

Instructional Rationale: A parameter-exploration pattern fits this Apply-level objective because the learner needs to test several budget and platform combinations and immediately see the arithmetic consequences, rather than watch a single pre-computed scenario play out.

Canvas layout:
- Left (450px): a simple bar showing devices purchased vs. students still needing a device
- Right (150px): control panel

Interactive controls:
- Slider: Grant amount, $500-$10,000, step $250, default $3,000
- Dropdown: Platform (Chromebook $250, Windows $450, macOS $950, Custom price)
- Input (number): Custom per-unit price, enabled only when "Custom" is selected
- Input (number): Number of students in the club, default 12
- Button: "Reset to Defaults"

Behavior:
- Devices purchasable = floor(grant amount / unit price), recalculated live as any control changes
- Remaining budget = grant amount - (devices purchasable x unit price), displayed in dollars
- Coverage = "X of Y students have their own device" compared against the student-count input
- Bar chart updates immediately; no animation delay, since this is a calculation tool, not a simulation

Default parameters: $3,000 grant, Chromebook selected, 12 students -- resulting in 12 devices, $0 remaining, "12 of 12 students covered"

Implementation notes: p5.js canvas with createSlider, createSelect, and createInput controls parented to the sketch's own control div; recompute on every draw() call rather than only on change events, since inputs may be adjusted with arrow keys.

References