---
title: NumZoo
emoji: 🦁
colorFrom: purple
colorTo: pink
sdk: gradio
sdk_version: "6.17.3"
app_file: app.py
pinned: false
license: apache-2.0
tags:
  - flux
  - text-to-image
  - kids
  - education
  - math
  - track:backyard
  - sponsor:modal
  - achievement:offgrid
  - achievement:welltuned
  - achievement:offbrand
  - achievement:fieldnotes
---

# 🦁 NumZoo

A mental math app for kids — answer questions, earn cute AI-generated animal images as rewards!

> 🏆 **Built for the [🤗 Hugging Face "Small Models, Big Adventures" hackathon](https://huggingface.co/build-small-hackathon).**
> A small (4B) image model, fine-tuned with a custom LoRA, turned into a delightful kids' reward loop.

## How it works

1. Enter your name
2. Pick your favourite animals 🐾 and places 🌍 (used to personalise reward images)
3. Answer math questions — every **3 correct answers** earns a reward image
4. Level up: **Additions → Subtractions → Multiplications → Mix**

### See it in action

▶️ **[Demo video (Loom)](https://www.loom.com/share/c565cba49f2c4ad1bfb428e38ff4b629)** · 📣 **[Launch post](https://x.com/goooums/status/2066500943676399814)**

|   1 · Pick animals & places    |       2 · Solve math       |      3 · Earn cute reward      |
| :----------------------------: | :------------------------: | :----------------------------: |
| ![picker](docs/app_picker.jpg) | ![quiz](docs/app_quiz.jpg) | ![reward](docs/app_reward.jpg) |

## Levels

| Level | Operation         | Goal      |
| ----- | ----------------- | --------- |
| 1     | ➕ Additions       | 5 correct |
| 2     | ➖ Subtractions    | 5 correct |
| 3     | ✖️ Multiplications | 5 correct |
| 4     | 🎲 Mix             | Endless   |

## Image model

Rewards are generated with **FLUX.2-klein-4B** (4B params, Apache 2.0) via 🤗 Diffusers,
plus a **custom NumZoo style LoRA** (below). Images start generating in the background as
soon as the quiz begins, so a reward is usually ready the moment it's earned.

## ✨ Custom AI art: the NumZoo LoRA

Out of the box, FLUX.2-klein renders the same prompt in wildly different styles — often
photorealistic — which doesn't fit a soft, cozy kids' app. So we fine-tuned a **style
LoRA** that pins every reward to the same kawaii children's-book look.

**Before → after** (same prompt: *"a cute baby panda on a snowy mountain top"*):

|       Base FLUX.2-klein-4B       |         + NumZoo LoRA          |
| :------------------------------: | :----------------------------: |
| ![before](docs/panda_before.jpg) | ![after](docs/panda_after.jpg) |
|   photorealistic, inconsistent   |   cozy, on-brand, every time   |

More rewards from the LoRA:

|                               |                                   |                           |
| :---------------------------: | :-------------------------------: | :-----------------------: |
| ![bunny](docs/lora_bunny.jpg) | ![unicorn](docs/lora_unicorn.jpg) | ![fox](docs/lora_fox.jpg) |

### How we made it
1. **Dataset** — 54 cozy scenes generated with **Qwen-Image** (12 animals × 10 places,
   incl. multi-animal/multi-place combos), captioned `NUMZOO. <content>` with the style
   left *undescribed* so the trigger word carries it. See
   [`scripts/generate_dataset.py`](scripts/generate_dataset.py) and
   [`training/`](training/) for the images + captions.
2. **Training** — LoRA (rank 32, 1500 steps) on `FLUX.2-klein-base-4B` via
   [ostris/ai-toolkit](https://github.com/ostris/ai-toolkit), running on a **[Modal](https://modal.com) A100** (~45 min, serverless GPU).
   Reproducible setup in [`training/lora_trainer/`](training/lora_trainer/).
3. **Inference** — the LoRA loads on the distilled 4-step klein in `image_generator.py`;
   the app simply prepends the `NUMZOO` trigger to every prompt.

**Published LoRA:** 🤗 [goumsss/numzoo-flux2-klein-lora](https://huggingface.co/goumsss/numzoo-flux2-klein-lora)

## Run locally

> Requires Python on Apple Silicon (arm64). Recommended: [Miniforge](https://github.com/conda-forge/miniforge).

```bash
# 1. Install dependencies
~/miniforge3/bin/pip install -r requirements.txt

# 2. Accept FLUX.2-klein-4B license on HuggingFace
#    → https://huggingface.co/black-forest-labs/FLUX.2-klein-4B
#    Then log in:
hf auth login

# 3. Run
~/miniforge3/bin/python3 app.py
# Opens at http://localhost:7860
# First run downloads ~23GB of model weights (cached after that)
```

> On standard Python/pip (non-Apple Silicon):
> ```bash
> pip install -r requirements.txt
> python app.py
> ```