Lattice Multiplication

[SweetPea]

My dc school teaches lattice multiplication. This was new to me. Curious to see if this is being taught widespread across the country (we're in UT). I prefer the "old" method, but understand this. Still deciding what I really think!

[Bang!Zoom!]

I've seen Lattice Multiplication in practice; I do not feel confident that it is standard math expression but just another way to solve.

 

My oldest daughter used this style in experimental math solving and I don't think it helped her much. I think that if the math style "changes" to standard, it can cause broken steps in operation. We did not have a positive experience with it.

 

Someone else will be along to offer a more academic view of the value of this style.

 

I'm just speaking from personal.

[Jamauk]

A friend of mine (very, very, very anti homeschooling) teaches Spec Ed Math and she told me it doesn't matter if my kids are especially gifted, Spec Ed or just average, but to run FAR FAR FAR away from Lattice Multiplication.

 

She said she almost went bald this year from pulling her hair out trying to teach it! From what I understand, no one (even top mathmaticians) actually understands why it works, just that it always does.....???

 

I've not looked too closely at it, but it seems to skip steps to me and I'm not sure kids will truly grasp the fundamentals of multiplication if they rely on the lattice method.

 

Also, have you seen how much paper one problem takes up?!?:glare:

[EKS]

The lattice technique bothers me because it doesn't seem to directly reinforce the concept of place value, while the traditional algorithm does if it is taught correctly (for example, using zeros rather than x placeholders or nothing).

[chepyl]

If it is taught to the exclusion of the traditional algorithm, it means kids must start using calculators very early. It becomes too tedious after 3 digit numbers. I don't like the method. I would be teaching traditional multiplication at home.

[gingersmom]

Its the worst.

 

I actually had to go to my daughters school to learn how to do it. I taught her the regular old fashioned way at home.

 

When she hit middle school no one used it, including the math teachers.

[SweetPea]

You've confirmed my thinking that the traditional method is the way to go (which I've taught my ds). My ds (4th) was wanting to understand this new approach....hates not to get things. Well I've been going through all the papers brough home and finally found 1st day note from his math teacher which states "children may complete problems with whichever method they choose; they just need to show their work" We're going to skip Lattice Multiplication :lol:

[Wee Pip]

I think there is a video on youtube that explains lattice multiplication and why it works (it might be a khan academy video). The video explains the place value in the lattice and why it gets you to the right answer. But no, the place value is not obvious, and lattice multiplication outwardly appears to be more of a parlor trick:) It is not something I will teach my children.

[EmilyK]

I seem to remember on the living math site livingmath.net (or maybe the associated listserv?) there was positive discussion of lattice multiplication, and maybe Julie or someone else had a daughter who really liked it. I think I watched a you tube video of it.

 

I think if you have all the time in the world (and homeschoolers are more in this situation than others) then it could be good to learn lots of alternative ways to do something, since one of them may particularly resonate with your child.

 

That said, I've had a pretty negative experience with the public school math approach. In theory, and as a homeschool approach, I like the more living math / constructivist approach. But in practice, both of my sons have ended up being far, far behind in math when they ended up going to private school from public school. And this was with us reading a lot of living math, discussing math in everyday life, etc. I do think that helped them have good number sense, but since I was a math whiz, raised by a mathematician mother, I feel embarrassed that they weren't farther along in the traditional skills like multi-digit multiplication and division. Those skills were not taught at all at their public elementary school.

[jenbrdsly]

Wow! I hadn't seen that it years. I had to look it up to remember. Lattice multiplication is the exactly opposite of teaching math from a Constructivist perspective, which is very anti-math-magic.

[jjins]

I had my son do standard longhand multiplication before I showed him lattice math and WHY it works.

 

To try and put this in words...

 

I showed my son the three digit times three digit multiplication problem. We worked it out long hand.

 

Then working out the EXACT same problem we start the lattice style. First we discussed where the two numbers being multiplied go. Then we worked through each step of the problem. I reminded him that if you multiply 5 time 5, you get 25, you carry the 2 and place the 5 here... however, for this you are going to place your 2 on the upper part of the box, because it is part of the next place value, and put your 5 in this box so it is lined up with place value.

 

We multiplied by units, tens and then hundreds before moving on. Then we looked at the diagonal lines for place values. We added the units, no big deal here.

 

However, when we added the tens, there was something different. So we looked at the first problem, I pointed out how we had carried the 2 from multiplying the 5 x5 and then later added it in to the next number. For lattice you do all the adding AFTER multiplying. You are still doing the same steps you are just changing the order!

 

Okay, so this is VERY hard to do with words only and I searched on youtube for a good video... this is the best one I could find in my quick searching. What I do not like about this sample is that the sample problem would not have carrying, therefore does not show as well how similar the two ways of doing multiplication are.

 

 

I hope this helps. I was a lattice hater, but I think the secret was that I did not understand how or why it works. I knew how to do it, but had not figured out or been taught why it works.

 

Also, for fun math check out the second video on this site:

http://vihart.com/

 

 

Mind you, much of what she has done is VERY interesting (albeit FAST), however the video I am suggesting you watch is the one that relates to this thread.

[BabyBre]

...run FAR FAR FAR away from Lattice Multiplication.

 

 

:iagree:

 

If it is taught to the exclusion of the traditional algorithm, it means kids must start using calculators very early. It becomes too tedious after 3 digit numbers. I don't like the method. I would be teaching traditional multiplication at home.

 

ABSOLUTELY teach the traditional algorithms at home. Teach them to mastery and, ideally, before they get those "fuzzy" methods ingrained too deeply.

 

There are a couple different "lattices" out there and I don't know if this one is the one they're teaching at your school, but this is a favorite video of mine explaining the rediculousness of reform methods and programs.

 

 

Over the last decades, it has become the norm in education. And in other news, the US ranks 25th in the world in math education. :glare:

[tex-mex]

Very common in any public school that uses Everyday Math -- been around for more than a decade and back when I taught in the late 90's, parents complained over lattice multiplication. Blame the textbook publishers.

[BabyBre]

Very common in any public school that uses Everyday Math -- been around for more than a decade and back when I taught in the late 90's, parents complained over lattice multiplication. Blame the textbook publishers.

 

 

Publishers are businesses and they're behaving the way businesses behave, that is, producing a product for which there's demand.

 

Blame lies on the district administrators who continue to remain married to reform programs despite the evidence that they don't work, and who tie their teachers' hands to do anything about it by micromanaging their classrooms with excessive regulations. Districts (or states, depending) are in control of what is taught, when it's taught, and how it's taught, yet they put the blame on anyone and everyone but themselves.

 

They blame the community by saying there's not enough support, financially or otherwise, even though they may spend upwards of $20,000 per student.

 

They blame the teachers whose hands they tie and whose talents they oppress, and threaten to fire them when they can't perform monumental tasks with inferior tools.

 

They blame the parents who aren't "involved" (i.e. picking up the slack by teaching their kids at home what teachers don't have time or support to teach them in school).

 

They blame the students for being "unmotivated", "slackers", "bad apples", or "jerks" (i.e. children who are products of their environments). I've heard each one of these titles applied to students by adults who are paid to help them.

 

They even blame math. "Math is hard" is their explanation for their failure!

http://www.spokesman.com/stories/2011/aug/14/remedial-math-routine-for-local-grads-at-ccs/

 

:rant:

 

I do apologize for the rant, but there's a lot of blame flying about with regard to education. Let's make sure it lies where it's deserved - at the top with those in control.