Embarrassing 4th grade math problem...

[crs7568]

Well, at least it is embarrassing for me because I have to go through ridiculous machinations to figure it out.

Here is the problem: "Tyesha and Eric together have 29 posters. Eric has 7 more posters than Tyesha. How many posters does each child have?"

What is a simple formula that can be used to figure this out? I can't believe my math skills are challenged already in 4th grade!

 

[mickeyboat]

Eric has 18, Tyesha has 11. I don't know about a formula.

Denae

 

[Rajah]

x + x + 7 = 29
Eric = x + 7
Ty = x

 

[KarenB]

One strategy that is hard for us parents to understand is "Guess and Check." I have always wanted a formula or equation to figure out this type of word problem, but local textbooks have the kids use a Guess and Check method. This allows them to get started, then use their math knowledge to decide what numbers to try to get closer, then finally come to a solution.

 

[CathrynRose]

Well, at least it is embarrassing for me because I have to go through ridiculous machinations to figure it out.

Here is the problem: "Tyesha and Eric together have 29 posters. Eric has 7 more posters than Tyesha. How many posters does each child have?"

What is a simple formula that can be used to figure this out? I can't believe my math skills are challenged already in 4th grade!

29 - 7 = 22
22 / 2 = 11 (Tyesha)
11 + 7 = 18 (Eric)

 

[becka]

I don't know for sure but on the 4th grade level I doubt they are doing algebraic equations so they may just be looking for a guess and check here. Just pick a reasonable sounding amount like Tyesha has 8 so Eric would have 7 more or 15 but 15 + 8 only equals 23 so then they try Tyesha has 9 so Eric would have 16 and 16 + 9 = 25, etc... until they get the right answer.

 

[tnkbl]

Start with 29 beans and make two separate piles. Assign one pile to each child. Move 1 bean at a time from T's pile to E's until you have 7 more in E's pile. You have to count often to make sure that you really end up with 7 more for Eric.
We start this in second grade down south.

 

[MouseWorshipin]

I'm thinking this is more like 6th, maybe 7th grade, but...

Posters = x
Tyesha we don't know about, so she's (he's?) x
Eric we know has more, so he's (x+7)

x + (x+7) = 29
x + x + 7 = 29
2x + 7 = 29
2x = 22
x = 11

Plug it back in:

11 + (11+7) = 29
11 + 11 + 7 = 29
22 + 7 = 29
29 = 29

 

[rlovew]

I teach 3rd grade. They want the child to guess and check until they find the answer. I like the jellybean idea. I generally show my students the algebra and a couple pick up on it and the rest just stick with the guess and check. They are introduing algebra to students younger and younger hoping that seeing it often will help it become easier to grasp.

 

[crs7568]

I knew I could count on some Dis smarties to help me out. I think it must be that they are looking for the guess and check method. It just seemed so laborious. My daughter has not learned algebra yet so the formula method made no sense to her.

Anyway, thanks for the great formula breakdowns! I will remember to return the favor and be quick to respond the next time someone has a question about English homework.

 

[jackskellingtonsgirl]

My 4th grade DS absolutely has Algebra problems just like that. They are a nightmare! He has a terrible time with plain math, like multiplication, so problems like that just blow him away.

One night he had one that had a little chart about movie tickets. There were X number of tickets sold at 9 PM and Y number of tickets sold at 11 PM, but they were different prices. The total $ revenue was Z, so how much did the tickets cost for each show? Who the hell knows? Why does this have to be so HARD? DH actually got up the next morning and messed with that until he figured it out, then he explained it to DS when he woke up. There is no way DS could have done it by himself! Not even for all the tea in China! I couldn't do that problem by myself, either, so we can see where DS gets his math ability!

At least in the problem listed in the OP you can subtract off the extra posters that the kid with more has and divide what's left in half. Pretty straightforward. It's a wonder any of us can functionin our daily lives without being able to do 4th grade math!

 

[ducklite]

29 - 7 = 22
22 / 2 = 11 (Tyesha)
11 + 7 = 18 (Eric)

That's how I would have solved it as well.

Anne

 

[MouseWorshipin]

I teach 3rd grade. They want the child to guess and check until they find the answer. I like the jellybean idea. I generally show my students the algebra and a couple pick up on it and the rest just stick with the guess and check. They are introduing algebra to students younger and younger hoping that seeing it often will help it become easier to grasp.

Algebra is not hard! If you can lear to add 2+3, you can learn anything! It is just a matter of taking it step by step, and not trying to figure out some-kind-of-way to solve this problem or that. If you use the basic principles, they serve you all the way through, right up to Calculus. (I didn't go beyond Calc, but I'm sure they're good after that, too! ) Putting in smilies 'cause I know it looks like I'm yelling - math excites me! Hence the !!!s.

I love math. Teaching kids to "guess" seems silly. Math, of all things, is not a guessing game. Teaching them how to do it correctly, at each level, would (I think, I could be wrong) serve them better.

We didn't have "guessing" math, nor did my kids. But they did have a brief stint in "creative spelling," where 1st graders were taught to guess, and no spelling was "wrong." It vanished, though.

 

[paigevz]

Teach your child the simplest way to do a problem like that is to start with dividing the total by the number of groups needed.........in this case, 2 groups for the two children.

29 divided by 2 is 14 1/2. They can't have half a poster, so immediately assign one more and one less, so 13 and 15 is 28, need one more on the high end, so 13 and 16 is 29. Now just keep going one up and one down until the answer makes sense. 12 and 17, 11 and 18.........and now your difference is 7, as requested.

If your child has a problem like, which 5 numbers in sequence equal 100, she can use the same method. 100 divided by 5 is 20. To get them in sequence, one up and one down from 20, then again, to get 18,19, 20, 21, 22 which equals 100.

They aren't so much looking for guess and check,as trying to get the child to develop a strategy using number sense. Some kids need it directly taught, though, and often, that is not done. So some will simply sit and make tallies or wild guesses until they get close, then they can figure it out. That's frustrating and not really helping them, as evidenced by them using the same frustrating strategy next time. Hopefully, your child's teacher will be asking the kids to share strategies and they will look at different ways of approaching the problem in class. If she doesn't, you need to do it yourself so your child will see what is happening with the numbers..............

 

[becka]

Algebra is not hard! If you can lear to add 2+3, you can learn anything! It is just a matter of taking it step by step, and not trying to figure out some-kind-of-way to solve this problem or that. If you use the basic principles, they serve you all the way through, right up to Calculus. (I didn't go beyond Calc, but I'm sure they're good after that, too! ) Putting in smilies 'cause I know it looks like I'm yelling - math excites me! Hence the !!!s.

I love math. Teaching kids to "guess" seems silly. Math, of all things, is not a guessing game. Teaching them how to do it correctly, at each level, would (I think, I could be wrong) serve them better.

We didn't have "guessing" math, nor did my kids. But they did have a brief stint in "creative spelling," where 1st graders were taught to guess, and no spelling was "wrong." It vanished, though.

I agree algebra is not hard but most 4th graders do not possess the ability to grasp the abstract concepts taught in algebra. These type of problems and yes, even guess and check, help to develop as one poster said a number sense. Guess and check is really more like educated guess and check in the best sense. It is hard to teach number sense but hopefully after working with teachers on these types of problems students can get a better handle on it and will learn techniques that will help them later in their mathematical studies.

Trying to teach actual algebraic equations to children whose minds are not ready to grasp such a concept could be damaging to their further enjoyment and learning of critical math concepts.

Of course what do I know....I only have a degree in math and believe me I went WAY further than Calculus in college!

 

[Daxx]

I don't know for sure but on the 4th grade level I doubt they are doing algebraic equations

Are you kidding me?! We do algebraic equations in Kdg.! We have the following type of equations (among others) to figure out:

** + = ****
* ***

3 + ___ = 7

I ask them to tell me how many stars are in the first column ... and ask them if it matches the number underneath the stars. Then, I tell them to count how many stars are at the end, after the equal sign and if it matches the number underneath the stars. Then, I have them to add one star to the blank space and ask them to count all the stars. If it doesn't add to 7, they add another star until the two combined add up to 7. Then, they draw a circle around the stars in the 2nd column and count them and transfer the number to the blank space below.

Every math unit in my NY State books has an algebra section and I am required to teach it. So, yes ... they are teaching algebra in the lower grades. I can vouch for that!

~Daxx's Wife

 

[becka]

Are you kidding me?! We do algebraic equations in Kdg.! We have the following type of equations (among others) to figure out:

** + = ****
* ***

3 + ___ = 7

I ask them to tell me how many stars are in the first column ... and ask them if it matches the number underneath the stars. Then, I tell them to count how many stars are at the end, after the equal sign and if it matches the number underneath the stars. Then, I have them to add one star to the blank space and ask them to count all the stars. If it doesn't add to 7, they add another star until the two combined add up to 7. Then, they draw a circle around the stars in the 2nd column and count them and transfer the number to the blank space below.

Every math unit in my NY State books has an algebra section and I am required to teach it. So, yes ... they are teaching algebra in the lower grades. I can vouch for that!

~Daxx's Wife

You are teaching algebraic concepts which to me is different than teaching algebraic equations. Mastery of those basic math concepts will allow a child at the appropriate level to learn to solve algebraic equations. A subtle difference I suppose but you can't tell me that the OP's child was supposed to come up with 2x + 7 =29 and solve. They are however learning concepts that will help them solve 2x + 7 = 29 in a few years.

 

[Daxx]

You are teaching algebraic concepts which to me is different than teaching algebraic equations.

True ... but my students also have to know how to write these out and spend time putting problems like that demonstrated together on their own. I think that's a bit much for Kdg., but it's what NY State expects me to teach!

but you can't tell me that the OP's child was supposed to come up with 2x + 7 =29 and solve.

I know I can't tell you that ... but it sure seems like it to me!!!!

 

[MouseWorshipin]

You are teaching algebraic concepts which to me is different than teaching algebraic equations. Mastery of those basic math concepts will allow a child at the appropriate level to learn to solve algebraic equations. A subtle difference I suppose but you can't tell me that the OP's child was supposed to come up with 2x + 7 =29 and solve. They are however learning concepts that will help them solve 2x + 7 = 29 in a few years.

But I don't understand why the kids aren't just taught the things they need to know at each level. K- these are the numbers. 1st grade - here's how you add. If they learn what they need to know along the way, there is no giant hurdle they need to be prepared to leap.

I think that presenting material kids aren't ready for and telling them to guess how it is done will just lead to confusion and frustration. But that's just me.

 

[becka]

But I don't understand why the kids aren't just taught the things they need to know at each level. K- these are the numbers. 1st grade - here's how you add. If they learn what they need to know along the way, there is no giant hurdle they need to be prepared to leap.

I think that presenting material kids aren't ready for and telling them to guess how it is done will just lead to confusion and frustration. But that's just me.

But the point of these types of problems is so that there is no giant hurdle when they hit pre-algebra, algebra and higher math.

I am sure as a child you had problems in early elementary school after you learned to add that asked you to fill in the blank like Daxx provided (well without the stars). If you ask a first grader to look at this:

3 + __ = 5

and fill in the blank what is an elementary aged kid going to do. Are they going to subtract 3 from 5 to get 2? No. More than likely they will start with plugging 1 in the space to get 4 - realize that is wrong and then try 2. It is really not that much different than the 4th grade example with guess and check but by 4th grade it just adds a few more layers for students to look at. It is this type of thinking about "variables" early on that eventually will lead a jr. high kid to be able to solve 3 + x = 5 and to be able to understand why x = 2 and to learn how to actually solve rather than guess and check.

If elementary schools just did basic math until they hit pre-algebra without these kinds of lead-up problems that would be a big hurdle IMO.