The Unbearable and Unproductive Number Bonds

I was going through my son's maths homework today and the number bonds thingy came back again in counting money.

I find number bonds to be rather unbearable and unproductive. It is like you have to do additional steps to get the answer when a simple subtraction will provide the answer. Wouldn't the method below be more efficient?

To explain the number bonds method of subtracting money, I had to explain to my son why - x - is positive and - x + is a negative - this is something out of concept for a primary 3.

Take the number bond above as example.

From the number bond, the equation looks like this 22.65+3 -(3+0.25), if you break open the brackets and you have explain multiplication of positive and negative to a primary 3 kid. As such, I had to stick to a simple routine to get him to under how this works.

You start first by taking the subtrahend ($3.25) and break it into two - one part whole dollar ($3) and the other part cents ($0.25).

From the minuend ($25.65), you break it into two but the right bond should be the same as whole dollar from the subtrahend ($3).

Then you take the left bond of the minuend ($22.65) and you minus the right bond of the subtrahend ($0.25) to get the answer - $22.65-$0.25=$22.40.

There were some questions that required my son to break it into number bonds and yet do the tradition subtraction method to get the answer.

Can somebody explain to me the benefit of using number bonds?

Comments

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