Also, this is not a standard 5th grade math assignment. To do it purely with logic and no trial and error takes some thought, particularly when getting to the third column with 1, 5, 6, and 7 left over if done as easy as possible.
I solved for the 4, then did 1 instance of trial and error with the top row before I realized there wasn't enough info. I can see how adults that haven't used their minds in decades would have problems with this.
Much of current math in the US is puzzles and activities like this. It depends on the teacher, but many are using these "fun" activities to try and engage kids.
This is essentially Sudoku, but this one has a situation with 5 equations and 6 variables. So with trial and error it might be relatively easy, but to do it "properly" with equations is mathematician level difficulty. Or just code it and do trial and error.
1 year ago3 points(+0/-0/+3Score on mirror)1 child
Shit, I hit the delete button instead of edit. That’s what I get for tabletposting. *They* violated the precepts when trying to work out the completed column on the right. They ignored OOPS.
It's like a simple form of Sudoku. You always do the line in which only 1 is missing.
1. Column: 9 - 4 / 8 * x = 7 --> x is 4.
4. Row: x + 1 + 7 - 4 = 8 -> x is 4. It's the same x as above.
3. Column: 6 - 5 + y - 7 = 3 -> y is 9.
3. Row: 8 - 5 = y - z * 2 -> y is 9 as above, therefore z is 3.
From here on you have 2 or 3 missing in every line. That means we have 5 equations each with 2 or 3 variables (6 in total). We need to figure out a viable constellation of values so that all 5 equations are correct. So first the ones with 2 missing (plus a simplified form for later):
I 1. Row: 9 + a - 6 = b - 3 | b = a + 6 | a = b - 6
II 2. Row: 4 + c * 5 - d = 6 | d = 5c - 2 | c = d/5 + 0.4
III 5. Row: 7 = e * 3 - f - 2 | f = 3e - 9 | e = 3 + f/3
IV 2. Column: a = c + 5 - 1 - e | a = c - e + 4 | e = c - a + 4 | c = a + e - 4
V 4. Column: b = d - 3 - 4 + f | b = d + f - 7 | d = b - f + 7 | f = b - d + 7
So we have to combine equations. In theory there can be multiple solutions, but we are restricted to integers from 1 to 9. Each variable must be one of those.
I and IV: c - e + 4 = b - 6 -> b = c - e + 10 | e = c - b + 10
I and V: a + 6 = d + f - 7 -> a = d + f - 13
II and V: 5c - 2 = b - f + 7 -> b = f + 5c - 9
II and IV: d/5 + 0.4 = a + e - 4 -> a = d/5 - e + 4.4 | e = d/5 - a + 4.4 | d = 5e + 5a - 22
III and IV: 3 + f/3 = c - a + 4 -> a = c - f/3 + 1
III and V: 3e - 9 = b - d + 7 -> b = 3e + d - 16
So what did we get? We managed to mix up variables. But otherwise nothing really. But if we get just 1 variable, we'd get all others too. The problem is that we can't. So we'll need to trial and error. But, we have a lot of options, and I assume some multi-dimensional math or drawing would be required. I could write a program to do it, or I'd have to spend time to figure out a way to meaningfully draw it to a paper.
But this is way too hard (almost impossible) for fifth grade. At that time I was by far the best in class in Math, and even I would have struggled with it. Maybe with trial and error, and with that 1-9 hint, but to do it properly takes quite some time and skills that are... possibly even inaccessible to 95%+ of people (non-humans not counted). And for the remaining ones it would take quite some time. ~1% or less would be able to do it without significant time.
1 7
2 8
9 3
4
5 6? (from top left to bottom right)
Also, this is not a standard 5th grade math assignment. To do it purely with logic and no trial and error takes some thought, particularly when getting to the third column with 1, 5, 6, and 7 left over if done as easy as possible.