783 = 421 + ...

For not very serious reasons the teachers in La Ribera, Baja California, Mexico have closed the school for several days.
They say it is because of the rain.
But that needs hardly an umbrella.
So maybe they were just needing a break.

As a consequence, the children of the Gonzales family are at the rancho at Punta Boca del Salado where the Fuso Szulc is located these days.
And these kids ask if they can get classes again.
Not in English, geography or history.
No, they want mathematics.

Okay, okay, in the class of this bush school the children themselves make the decisions.

One effort that is made teaching the glorious kids is that each time something new and surprising is offered to them.
To avoid they get bored with again regular mathematical challenges.
Like 25 + 47 = how much ?

Now, the great thing with kids is that when it is announced that this time it will be completely different from the last time, no kid protests.
They look while thinking and reflecting, but not one says: "Hold on, we don't want anything new and different, Mr. Teacher".
They all accept and await openly what is coming at them.

Therefore they got this sum to work on:

72 = .. + ..

They could fill in themselves numbers that totaled 72.
This was explained and off they went.

It worked well.
They pained their brains and came up with solutions like 25 + 47.

Until clever Juan came with an intelligent solution to 5899 = …. + ....
He returned his paper with this: 5899 = 5898 + 1

Of course he was applauded by everybody and he got two stars: the rewards for every good solution.

However, as the professor, it can never be allowed that the students outsmart with tricks like 5898 + 1
A kind of superiority must always be solidly there in order to survive.

Therefore the new sum was 783 = 421 + ...
A groaning "Aaaaaiiiii Miguel" came from every student.
How to tackle this one?

Observing them work hard on this new challenge, it was noticed that none got the idea to remodel the sum.
Changing 783 = 421 + … into 783 - 421 = … to find the solution.

When eventually that trick was explained, from then on it was all piece of cake.
And they felt proud they had learned to solve a complicated sum in a new way.


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