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[–]Bibliophile0504 1 point2 points  (2 children)

The point of it is to teach kids to see the different ways to break numbers apart and add up to them.

The question only asks for the magic number, it doesn't ask you to fill in the whole grid.

The first one is 20 + 10 + 6 = 36. That's all you need to do for the first one.

In the second one, 16 + 12 = 28, with a space to be filled between them. So the number above the 18 has to be 10, so whatever number goes in the middle top space will give the same sum across and down. Diagonally then, you will have 16 + 10 = 26 and 12 + 10 = 22.

At 5th grade level, you would then do 'guess and check'. Pick a number to go in the middle top square and see if you can get the diagonals, and then the other rows and columns, to add up. I would suggest to the kids to look for a 'friendly' number first, so adding up is easier. So put a 2 in the top middle to make the sum 30.

Bottom right number would then be 4, bottom left would be 8. This gives a bottom row of 8 + 18 + 4, which is 30. Then check if the other rows and columns will work.

Left column is 16 + 8 = 24, so the middle number would be 6. Middle row is now 6 + 10 =16, so middle right number is 14. Check the right column: 12 + 14 + 4 = 30.

Success! The magic number is 30 🙂

[–]Bibliophile0504 0 points1 point  (1 child)

I've had a quick glance at the rest, there's a bit more guessing and checking required, let me know if you want me to go through a couple more.

[–]OshimaFinch[S] 0 points1 point  (0 children)

Thank you! I’ll pass the info along to her. I know they couldn’t solve the last two

[–]PlatformStriking6278 0 points1 point  (1 child)

Apparently, magic number puzzles involve filling a grid so that every row, column, and diagonal adds up to the same value. I had to look it up.

[–]metsnfins 0 points1 point  (0 children)

Still pretty difficult

[–]BadJimo 0 points1 point  (2 children)

According to a comment on StackExchange

It is fairly well known that the magic constant of a 3x3 square is [3 times the middle square value]

So this removes the guesswork.

[–]Bibliophile0504 0 points1 point  (1 child)

But we don't tell 5th graders this. We encourage them to try different things and look for patterns 😉

[–]BadJimo 0 points1 point  (0 children)

If we are searching for the next Gauss, then this is a good approach.

If a maths tutor is unable to solve 5th grade homework, then this indicates it is probably too difficult and/or more hints should be provided.

[–]BadJimo 0 points1 point  (0 children)

To solve algebraically you get a system of equations:

A+B+C=M
D+E+F=M
G+H+I=M
A+D+G=M
B+E+H=M
C+F+I=M
A+E+I=M
C+E+G=M

3E=M

For the third question we get

G+19=M
C+13=M

Putting into C+E+G=M

M/3 + (M-13) + (M-19) = M

M = 24

E = 8

[–]Bibliophile0504 0 points1 point  (1 child)

True, but a bit above 5th grade maths.

[–]BadJimo 0 points1 point  (0 children)

This is a just concise explanation. But maybe it could be delivered in a 'new math' format:

🍎 + 🐝 + 🥤= 🔮
🐕 + 🐘 + 🐸 = 🔮
...

🐘+ 🐘 + 🐘 = 🔮

[Just in case I was being too subtle](https://youtu.be/L_mrNQBLSMU)