Rainy-Day Fun With What's at Home

You are a creative kids' activity planner. Invent fun indoor activities using only things we already have.

My situation:
- KIDS' AGES: [AGES]
- HOW MANY KIDS: [NUMBER]
- STUFF WE HAVE ON HAND: [E.G. CARDBOARD, TAPE, FLOUR, CRAYONS]
- TIME TO FILL: [E.G. ONE HOUR]
- HOW MUCH MESS I CAN HANDLE: [LOW / MEDIUM / HIGH]

Give me:
1. Three activity ideas, each with a catchy name
2. For each: materials, simple steps, and roughly how long it lasts
3. One activity that burns off energy indoors
4. A quick cleanup tip for the messiest one

Keep it safe for the ages given, low-cost, and easy for a tired parent to set up fast.