How to teach your kid to design and build: from a sketch to a working marble run

A pile of cardboard boxes, a roll of tape and a free afternoon: some of the best learning happens right there. Building teaches kids to plan, test, fail and fix, the same cycle engineers use to design bridges and phones. And unlike a worksheet, you know right away whether it worked: the marble rolls, or it doesn't.

Why building is worth it

It's the engineering design process. The Next Generation Science Standards, used by many U.S. schools, ask students in grades 3 to 5 to plan and carry out fair tests in which variables are controlled and failure points are considered, to find parts of a model or prototype that can be improved. In plain words: build it, test it, find what breaks, make it better.

It's art, too. The National Core Arts Standards start with generating and conceptualizing ideas, then organizing and developing them, then refining and completing the work. A cardboard castle goes through every step.

Simple materials are best. The American Academy of Pediatrics notes that simple and inexpensive objects are some of the best ways to support a child's creativity. Boxes, tubes, tape and string beat most expensive kits.

Skill 1: Build something from a sketch

1. Sketch what you want to build.
2. Plan the sizes on your sketch.
3. Build it, checking your sketch.
4. Compare it to your plan.

Why sketch first? It's tempting to jump straight in. But a sketch makes you think about the parts, how they connect and how big each one is. Engineers and architects always start on paper.

Ideas: a cardboard house for a stuffed animal, a block tower with a bridge, a robot from boxes, a car with a cardboard body and bottle-cap wheels.

Compare, don't judge. "Your tower ended up shorter than the sketch. Why do you think that happened?" Differences between plan and result are where learning happens.

Skill 2: Fix a broken craft

1. Find exactly what's broken.
2. Pick the right glue or tape.
3. Ask a grown-up to help with hot glue.
4. Let it dry, then test it.

Fixing is engineering. You have to figure out why it broke, not just that it broke. A wobbly leg might need a stronger joint, not just more tape.

Match the glue to the job:

Hot glue guns get very hot. A grown-up handles it, or supervises closely if your child is ready. (More fixing skills in fixing things.)

The challenge: design and build a working thing

The mastery goal is to design and build a working thing, like a bird feeder or a marble run.

1. Sketch your design and how it works.
2. Build it, with a grown-up for any tools.
3. Test it and see what goes wrong.
4. Fix it until it works.

"Working" is the key word. It's not done when it looks right. It's done when the marble gets to the bottom, or the birds can actually eat from it.

Marble run tips: paper towel tubes cut in half lengthwise make great ramps. Tape them to a wall or a big box at a slope. The first try usually sends marbles flying off the curves. That's the test showing you where to add walls.

Bird feeder tips: a cleaned milk carton or plastic bottle with a hole and a perch. Test: does seed come out without spilling everywhere? Does it stay dry in rain? Then watch who visits.

Test more than once. Change one thing at a time, so you know what fixed it. That's the "fair test" part of the engineering standard. (More in running a fair test.)

Coaching tips

• Let it fail. Jumping in to fix it takes away the best part.
• Ask questions. "What happened right before it fell?" "What could make that joint stronger?"
• Keep a junk box. Clean boxes, tubes, bottle caps, string and scraps. Kids build more when materials are ready.
• Celebrate redesigns, not just finished products. "Version 3 is so much better than version 1!"

Make it a quest

In Family Quests, this is the Builder skill. Practice quests are build something from cardboard or blocks from a sketch and fix a broken craft, and the mastery quest is design and build a working thing (a bird feeder, a marble run). Quests with tools or hot glue list a grown-up to help. Start free.

Next: help your kid practice music, dance or art, or read about fixing things.