Thursday, October 4, 2012

DIY Balancing Scale

When my son came home from school with math homework that asked him to estimate the weight of objects, judging which was heavier, I knew it was time to make a DIY balancing scale. This idea is brainchild of Quirky Momma Deirdre Smith, aka JDaniel4’s Mom.

Construction is simple. I used a wire pants hanger from the dry cleaner, yarn, and two sturdy paper cups. At the two bottom ends of the hanger, I hung yarn, to which I tied a paper cup (I’d punched holes in the paper cup just below the rim).

The cardboard tube on the pants hanger kept the yarn from moving along the bottom of the hanger. Note: Make sure your cups hang equal distance.

Now hang over a door knob and get ready for some math fun!

My son grabbed lots of small objects. I grabbed a handful of quarters.

He put an object in one cup and balanced the scale with quarters in the other cup. We recorded the weights.

1 matchbox car = 4 quarters
1 calculator = 5 quarters
1 LEGO Ninjago spinner = 5 quarters
1 mini flashlight = 6 quarters
1 yoda writing pen = 3 quarters
2 rocks = 3 quarters

Now I asked him what object weighed the most. “Easy!” he said. “The flashlight!” I asked him how he knew that was the heaviest. “Because it took the most quarters to balance it.”

“Why not use rocks as a unit of measurement?” I asked. This required some thought. After a long pause, he said, “Because they’re not the same size?”

“YES! The quarters are a good unit of measurement because they all weigh the same. The rocks do not.”

I kept the questions coming. My son was up to the challenge. “If the yoda pen and the 2 rocks both took 3 quarters each to balance the scale, what conclusion can we form?”

“They weigh the same!” he said. We put them in the cups and, lo and behold, the scale was balanced. The hanger was level.

When I asked my son later what his favorite part of the day was, believe it or not, our DIY scale was it. I LOVE that my son loves learning!


  1. LOVE IT! Totally fun and thinking about money math... if we could see what weighs more to make 25cents...a quarter or 2 dimes and a nickel?

  2. It`s our DIY Balancing Scale

    Thanks, it`s very useful!

  3. This is fabulous. What year was your son in when he did this activity?
    Thank you for sharing such great ideas!