Hi All,
I am new to fourth grade, (which is enough of a challenge coming from second) with a tough class to boot. Many of the children have low skills and are having a tough time learning to multiply 2-digit numbers. I introduced lattice multiplication-just as an extra fun activity-and many of them are really taking to it.
My question is this:
Is there any reason I should make them do it the original/old fashioned way? I will continue to review the old way, and work to have them understand it, but are there any glaring drawbacks to letting them use lattice? It is getting to the point where we really need to move on, but I don't want to cause problems down the line when we get to division, etc.
Thank you in advance for your help!

It's great that they are taking to the lattice method. The old way will probably be taught in future years when they are expected to multiply with larger numbers. The knowledge that you are imparting is likely to transfer, though. I'd go on. You've got a boatload of other stuff to teach and you've got to do it whatever way works best for you and your students.

We teach partial products and lattice multiplication in 4th grade. They are taught the traditional way in 5th grade. My students are doing a great job with lattice, and they love it!

Our new Math program doesn't have the lattice algorithm in it, but I teach it anyway. Some kids just do like it better! If a particular topic or lesson is over just one of the algorithms other than lattice, I tell them that's the one they need to do and show, simply so I know they understand how to do it. Otherwise when doing problems I tell them to use which ever method they're most comfortable using. Out of my class of 22, I bet there are about 7 using one of the 3 types, so it's really interesting to see which students embrace which method.

We use Lattice Multiplication and anything else that can help! Students eventually learn the traditional way also. I have attached another example. Example Multiplication.pdf

Thank you all so much for sharing your thoughts. I am of the "whatever works for you works for me" school of thought, I just wanted to make sure it wouldn't bite me in the *you know what* later!

My district discontinued our teaching of Lattice. We are allowed to teach partial product but quickly switch to the "Old fashion way". The middle schools here want nothing to do with partial product and they will not let us teach partial quotient either.

The only drawback to doing lattice is that it is based on basic facts. They don't get as much practice with adding, place value, etc.

I am with you in what works for you is YOUR way. I tell the kids we will practice other ways but own the way that is the easiest for them. I actually have one of my slow little boys doing partial products and he's really getting it, whereas the brainiac isn't. Go figure!

Kids usually see lattice as a shortcut so they naturally gravitate towards it.

We too teach all of the methods mentioned including another that we call Multiplication Wrestling. Our middle school teachers really do want them to know how to do the traditional method. The lattice method gets time consuming drawing the grid as the kids get into the bigger problems. Our students also do a computer program daily called SuccessMaker and this program only uses the traditional method so the kids must use it.

3rd grade is Lattice year (we call lattice "kid way")...
4th grade is "adult way" -- with maybe some kids still doing lattice....
5th grade is def. "adult way"

I teach both ways. Some of my struggling students do much better with lattice. It's even in our textbook. However, the other members of my team only teach the "old" way.

word "Lattice" because that method confuses ME! However, I've found that there are a few students who can only do lattice at the beginning. It's funny b/c the others who already know compact think it's a blast to do lattice--like it's a game or something.

I ususally make a joke about how "You won't be using method in college, but for now, it's fine."

This was my first year with the lattice too...and the kids really like it! It hasn't caused us any problems with division, so I would just do whatever is working for your class! Good luck!

I love Lattice because the kids love it! I also teach Partial Products and have never taught the traditional method - I don't even know that I can! (This is my 4th year in Grade 4 after 5 in 2nd) Some of my students learned it in 3rd or learned it at home, but I do not teach it. We use Everyday Math (2001 edition) and the traditional algorithm is not presented in 4th, so I just don't teach it! I will not tell the kids they can't use it - if they know it, fine! I am also of the "whatever works for you" mindset, and I know that other methods will be taught in the coming grades.
Same goes for division. I am starting Partial Quotients this week - and being observed doing it! I am a huge supporter of this method and understand that EDM is setting the foundation in 4th grade for the future grades! I could go on and on, but don't want to hijack here!
Keep up the good work-If they can multiply, you've done a great job!

If your students are understanding lattice, they don't have to to know the traditional algorithm right now. I'm currently teaching them partial products and they love it. Especially after playing the game Multiplication Wrestling (Everyday Math). As they get more comfortable with the concepts we can then help them move to the traditional algorithm.

When using lattice, refer to the Distributive property. Great way of linking it back. Lattice has everything to do with place value. It's not magic. I wouldn't hide how it works from the students. Also show them how the "traditional way" works too with place value and the distributive property. You won't find the distributlive property in the CA 4th grade standards (it's in 5th) but this way on teaching addresses CA Math Reasoning 2.3.

I always try to incorporate as many different methods as possible with each topic I teach. Math is Math plain and simple. I hate that schools/teachers cling to the belief that there is one way to teach and that's it. If they understand one way better than another and they are successful...then let them be. I love lattice and I know the "regularly taught" way also. I always tell my students to do what works for them. I want them to be successful and not dwell on having to follow certain steps and do things a certain way. The "real world" does not require you to know any certain algorithm. Most people pick up a calculator anyway. Our students are living and breathing a digital era. I think everyone needs to embrace that more and more. "Old school" thought needs to be thrown out the window and students need to be able to explore and work in the way they understand. They need to be given the tools and then given the choice of what tools they want to work with.

Can you explain Multiplication Wrestling? I would love a game that helps my kiddos with their partial products...some of mine are really confused, the poor little things!

Over the year, my kids learn lattice, partial products, and the "old fashioned" way! I love to show them with a problem done each way all next to each other on the board and show how they ARE ALL THE SAME--just notated differently. If they understand place value well, they easily see that all 3 methods do the same thing.

At my school, we do not teach the students how to multiply the old way. We use lattice method and partial product to teach multiplication. The students love it and it gives them multiples ways to learn how to multiply.

The students draw 4 cards and create 2 2-digit numbers. They then write those as expanded notation (82 = 80 + 2). They must then set up the "wrestling" matches (think of it as tag team). Each number must "wrestle" both of the other numbers.

ie. 80+2 and 70+6 creates 4 problems.
1. 80x70
2. 80x6
3. 2 x 70
4. 2 x 6

They then solve each problem and record the product. The products are then added together. The person with the greater product wins 1 point and it's a best out of 3 match.