Need 4th grade math help please! ASAP

[ilovejack02]

And what is the point of this? I'm honestly curious what they hope to achieve with this stuff.

I would love to know too.

 

[DarthKTrava]

I would do the math WITHOUT the calculator. To me, that kind of math doesn't require the calculator. So no need to worry about which key is "broken"....

And who the heck comes up with this crap math to start with????

 

[MM27]

okay, I had a whole post typed out and lost my connection, so I'll try again.

I just finished teaching that lesson (4th grade EDM) last week. The lesson itself does not focus on the Broken Calculator. The lesson is about using variables in number sentences. If you look at the next page in the journal, you will see the work that goes with that lesson (don't have my book at home but I think it's page 74). In that lesson we work through the problems the "normal" way. So 15-x=10 would be solved by doing 15-10. No calculator for those.

The Broken Calculator is just another way for the kids to see what's going on in the problem. EDM is famous for showing multiple ways to solve one problem. Some of them are stupid, but as a teacher, I must show the kids all the ways. Believe it or not, I always get one or two kids that will have their ah-ha moment with the dumbest method of whatever we're doing.

Wait until you get further in. I was trying to show my accountant mother the lattice algorithm and she almost had a heart attack. She could not believe that "that's how kids need to multiply today?"

 

[georgina]

It doesn't get any easier! I was doing algebra 2 homework today with DD - matrix manipulation to solve systems of equations. I told her you will only have to learn this once, then from now on will use a calculator or computer.

 

[Schmeck]

And what is the point of this? I'm honestly curious what they hope to achieve with this stuff.

Some kids have difficulty with number sense - breaking down numbers into 100's, 10's, etc, can help them grasp the concept. Some kids can't estimate to save their lives (and you need to be able to do that if you drive a car - how far back is 100 feet?) and need the practice doing that. As stated by a PP, it can take many different approaches until all the kids get their ah-ha moment and can do the math.

I work with special needs kids - I use manipulatives, everyday examples, and about 2-3 other approaches getting kids to learn their multiplication tables, clock time, and word problems. It's an odd day when all the kids can do the math with just one example and one approach.

Right now I'm teaching 5 kids some Biology. That's 5 different approaches to Mitosis!

 

[manning]

A calculator shouldn't be needed to subtract two whole numbers, even by a 4th grader. If you have to use a calculator just enter 413 + 68 (press +/- key) and you will have your answer. Adding a negative number to a positive number is the exact same as subtracting.

If you have no +/- key get a better calculator.

You are posing this on a computer so it has a calculator. Click start -> Run -> type 'calc' -> hit enter.

did you mean.....68 press + press +/- press + 413 resulting in 345

 

[FireDancer]

did you mean.....68 press + press +/- press + 413 resulting in 345

Either gets the same answer. Since we are adding and no longer subtracting the order of operations is no longer important:

-68 + 413 = 345
413 + -68 = 345

Or you can dispense with the B.S. hypothetical broken calculator problem and just say solve for x however you would like...just like in the real world. I've written enough algorithms to know that there are often dozens of correct ways to solve a mathematical problem.

 

[EMom]

It's a good thing that I don't have kids and don't ever want kids, because I'd write on the assignment something to the effect of, "obtained new calculator which isn't broken".

Exactly....My answer (and I have a 4th grader) would have been, "Buy a new calculator or do the math with a pencil and paper." This is why I did not like geometry. I did well enough at it, but I never enjoyed it. The teacher would give us a triangle and we had to prove it was a triangle. (or something like that....it's been a long time since I took the class) I'd look at it and think, "Of course it's a freaking triangle. Just look at it. I knew how to recognize a triangle before kindergarten, so why do I have to prove it? Can't you give me a useful problem, like we had in algebra?" On some level, I knew the subject had a purpose, but on another level, so many of the problems annoyed me.

Remember the word problems about the two trains, each traveling toward each other at a certain speed? When would they meet? Would they crash? I wanted to say, "Look at the train schedule and get on a train that ISN'T on the same line as another oncoming train, you idjit." I resisted the temptation.