Learning Math – Mass using Lego blocks

Balancing object      YH balancing with Lego blocks

I have been thinking how to teach simple Math concept through play that will interest both my 8 year old XX and 6 year old YH.  I found so many resources in countless excellent blogs in the blogosphere.  One of them is on learning the concept of Mass using Lego blocks, a hanger and simple objects (found in Frugal Fun for Boys blog).  This is timely as XX happens to be learning Mass now.

First, get a hanger and 2 strings / ribbons.  Then, with 1 string / ribbon, tie a Lego block as a starting piece so that later on more Lego blocks can be fixed to it and the other string / ribbon tied to any object that is not too heavy.  Next, I got XX and YH to each draw a simple score board with 3 columns with the following:

1st column: OBJECT – What is the object being weighed?
2nd column: GUESS – How many Rectangular Lego blocks do you think will balance the object?
3rd column: ACTUAL – The final answer to the number of blocks that will balance the object.

Score board

XX and YH took quite some time to work on this score board, simply because they were busy decorating their score board, and we have not even started anything yet!

The kids enjoyed the activity and we tabulated the scores with guesses that have the correct answers.  2 points for the correct answer and 1 point for close to correct answer as a consolation.

* You would have noticed that the 2 pieces of score board in the picture look weird.  That’s because when we tabulated the score, YH was not happy that he lost to his sister by 1 point, and he did a naughty act by spitting some saliva on his sister’s score board.  I, too, did a naughty thing to scrap the saliva back onto his paper and there you see XX’s paper was cut short to remove the saliva portion, and YH’s paper was torn a hole as he tried to wipe off his own saliva.  It’s a norm to see them squabble over such minute things.  And equally a norm to see me deviate from the goody, yummy mummy supposed by-the-book way of punishment. 

Off center balance

Oh, and one interesting and unexpected learning from this activity is that when each child took turns to weigh their Lego blocks, they shifted the Lego string position.  This resulted in off center balance of the hanger as the centre of gravity had shifted.  When initially we saw that it took 10 Lego blocks to reach balance, it now could not balance and required 12 blocks instead due to the string shift.  I had a good opportunity to demonstrate that the position of the strings at the 2 ends of the hanger was important in determining the balancing act of the object and the Lego blocks.  And the kids were pleasantly surprised by this new finding! 

Try it with your kids and you will be off to great, simple fun learning!

4 thoughts on “Learning Math – Mass using Lego blocks”

  1. This is an interesting way of learning mass. I like the way you get your kids to guess the number of Lego blocks needed, and letting them test out their hypothesis. Great learning taking place here!

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