Comments on: Subtraction Roundup

By: Jim White

Jim White — Thu, 27 Feb 2025 10:13:24 +0000

This Subtraction Roundup is a fantastic collection of resources that make subtraction more engaging and intuitive! Your emphasis on both conceptual understanding and base-ten structure ensures that students don’t just memorize algorithms but truly grasp why they work. The interactive challenges, like Diffy Squares and Subtracting Reverses, provide excellent motivation for practice, making subtraction feel more like an exploration than a chore. Organizing videos by topic seems incredibly useful, especially for educators seeking targeted resources. However, your creative games and curriculum are equally valuable—perhaps a balance of both would be ideal. Looking forward to more innovative math content! 4o

By: Becky McCullison

Becky McCullison — Sat, 28 Dec 2024 20:46:00 +0000

Thank you for all the work you do and freely share! You are such a valuable resource for me and my students.
I appreciate you asking and yes, organizing content by operation is very helpful. I’ll be starting subtraction strategies with my students after this break and am excited to dive in with these activities. I love your videos and find them super helpful.

By: Dan Finkel

Dan Finkel — Tue, 05 Nov 2024 16:38:48 +0000

In reply to Jess. Thanks, Jess! Yes - we're hoping to have subtraction and division by heart out by Sept. 2025.

By: Jess

Jess — Mon, 04 Nov 2024 16:04:21 +0000

Wondering if you will be making a ‘subtraction by heart’ and a ‘division by heart’ game? And if not, any ideas for a DIY version to be used in one of our existing boxes from the other games? Thanks! Love your content, materials and games

By: Luca

Luca — Thu, 17 Oct 2024 06:20:35 +0000

I enjoyed this article very much. Having material organized by operation or other math topic is very useful according to me.

By: Sakthivel

Sakthivel — Sat, 05 Oct 2024 02:42:01 +0000

I agree with Elin. It is very helpful to have videos and other materials organized by operations or specific math topics. This organization makes it easier to see how math concepts progress from one to another.

Having them structured this way also helps in selecting appropriate games and rich tasks for the corresponding concepts.

Thanks a lot, Dan, for putting this together.

By: Elisabeth

Elisabeth — Fri, 04 Oct 2024 04:58:10 +0000

I also find it very useful when the information is organized by topic. Thank you for this subtraction roundup! My son just started bringing home subtraction homework and I will start using these strategies with him.

By: Julia

Julia — Wed, 02 Oct 2024 19:43:20 +0000

In reply to Dan Finkel. Wow, this videos link looks incredible, so many to for me (and, if relevant, also the kids) to watch. Thanks for sharing. Hugely grateful.

By: Dan Finkel

Dan Finkel — Wed, 02 Oct 2024 17:25:29 +0000

In reply to Julia.

We actually have a fair number of videos, in a few different categories: https://mathforlove.com/video/

By: James Brickwedde

James Brickwedde — Wed, 02 Oct 2024 17:01:57 +0000

Regarding your question about how to organize materials on the website, I would suggest a both/and approach. If I am looking for a specific topic, e.g., subtraction, having all things subtractions grouped is useful. If you are looking for number operations, having the addition and subtraction clustered together might be useful. While the permutations might get too complex to satisfy all viewers, various clustering of materials could be useful in how users search. I am rebuilding my own website (formatting failed an upgrade) so I am thinking similar questions as you.

On another note since we are in subtraction, and specifically your video explanation of the American Standard Algorithm (as opposed to, say, what Germany, Austria, Spain, and Mexico use), consider playing around with the following modeling of the decomposition of the top number. Using your example of 32 – 15, if students are choosing to use the standard algorithm and they are still in the modeling stages, instead of breaking the 32 into 20 + 12 [2 tens + 12 ones], have the student just slide the one ten over to the two ones so that 12 is represented at 10 + 2. The rationale for this is to scaffold student thinking away from counting off the five ones one at a time to physically model the derived strategy of 12 – 5 = 12 – 2 – 3. While the use of linking cubes make it easier to just break off the three ones from the ten, a base ten rod requires coverage/screening by the student. The above reduces the errors students make in “trading” one ten for ten ones.

Most of the students I have taught over the years don’t use the standard algorithm in favor of other fluid strategies. But when exposed to the algorithm with the understanding described above, at least have a better understanding of how it works and do less finger counting by ones over time as the derived strategies have been strongly nurtured. Would love your feedback on this.