K3L8 Little Bridge Builders

Lesson Duration: 45 minutes

Grade: K3

Preparation Time: 15 minutes

Learning Objectives:

1. Identify how changing shapes affects strength
2. Build bridges with different structures
3. Test different bridge structure

Materials Needed:
- Straws (10 per child)
- Masking tape/clay for connections
- Two blocks per child (for gap)
- Small weights (unifix cubes)
- Picture cards of beam and truss bridges
- Base plates (1 per child)
- Small bowl for weight testing
- Counting mat for weights
- Safety mats
- "Bridge Builder" stickers

Lesson Procedure

**3 mins - Welcome Time**
• Lead "Hello Song"
• Show bridge pictures
• Point to bridges: "What goes over?"
• Show toy cars crossing bridge

**7 mins - Discovery Chat: What is a Bridge**

• Show simple bridges:
- Beam bridge picture
- Truss bridge picture
• Identify parts:
- Bridge surface (top)
- Supports (sides)
• Use gestures to show crossing
• Introduce vocabulary: bridge, cross, strong

**10 mins - Hands-On Challenge 1: Explore Bridge Parts**
• Give each child:
- 2 blocks for gap
- 3 straws
- Tape/clay
• Together build:
- Place blocks (gap)
- Put straw across
- Test with finger

**15 mins - Hands-On Challenge 2: Beam Bridge**
• All children build beam bridge:
- Place blocks (gap)
- Put 2 straws parallel
- Add 1 straw on top
- Tape/connect parts
• Testing together:
- Add small bowl
- Count weights added
- Record numbers

- Compare results

**15 mins - Hands-On Challenge 3: Truss Bridge**
• All children build truss bridge:
- Keep blocks (same gap)
- Make triangle shapes
- Connect triangles
- Add top surface
• Testing together:
- Add small bowl
- Count weights
- Compare with beam bridge
- Celebrate strongest bridge

**5 mins - Clean Up**
• Collect materials
• Sort straws/weights
• Clean workspace
• Take photos

**2 mins - Wrap-Up**
• Show strongest design
• Give builder stickers
• Lead "Goodbye Song"