tag:blogger.com,1999:blog-5303307482158922565.comments2014-07-28T10:32:29.975-07:00Math Mama Writes...Sue VanHattumhttp://www.blogger.com/profile/10237941346154683902noreply@blogger.comBlogger1970125tag:blogger.com,1999:blog-5303307482158922565.post-6053630045890157002014-07-21T10:37:44.790-07:002014-07-21T10:37:44.790-07:00We will set up a pre-ordering mechanism soon. I wi...We will set up a pre-ordering mechanism soon. I will announce it here. If you don't follow my blog, you can check on playingwithmath.org for the announcement. Or email me, so I can let you know.Sue VanHattumhttp://www.blogger.com/profile/10237941346154683902noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-48091651434298015342014-07-21T10:25:10.886-07:002014-07-21T10:25:10.886-07:00I just missed the campaign! Is there a way to stil...I just missed the campaign! Is there a way to still donate and receive a book? I am working on my masters of science of mathematics teaching and still haven't thought of a topic for my thesis. I think this book might give me some inspiration. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-902220662004944992014-07-17T18:30:31.722-07:002014-07-17T18:30:31.722-07:00Hi Katie, thanks for requesting the picture. I thi...Hi Katie, thanks for requesting the picture. I think I've fixed it. (Blogger seems to have deleted most (all?) of my pictures. I don't have the time to put them all back up at once, but I can put them back when people request.)Sue VanHattumhttp://www.blogger.com/profile/10237941346154683902noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-83615056746072143662014-07-17T17:04:03.525-07:002014-07-17T17:04:03.525-07:00The picture of the task doesn't seem to show u...The picture of the task doesn't seem to show up anymore. Do you still have the picture. I'd love to be able to see the picture of the task and possibly try it out with my students! Thanks!Katie Kirchmeyerhttp://www.blogger.com/profile/18170564331962149349noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-12812552329917706702014-07-16T10:51:12.238-07:002014-07-16T10:51:12.238-07:00I love your blog, and plan to follow it.
I agree ...I love your blog, and plan to follow it.<br /><br />I agree that little kids should be introduced to the physical tools first. But my bad experience with physical tools makes me want a caveat: If a kid is particularly frustrated, or isn't doing as well with tools as they do with intellectual tasks, introduce the virtual tools soon. I was never good at constructions (compass always slipped?) and didn't enjoy them, until I discovered these sites. Sue VanHattumhttp://www.blogger.com/profile/10237941346154683902noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-12113926482946546482014-07-16T10:02:09.263-07:002014-07-16T10:02:09.263-07:00Sue,
Have been seeing you comment for a while on...Sue, <br /><br />Have been seeing you comment for a while on mathbabe and never realized you had such a great blog yourself. The on-line construction games are really fun and well-done. <br /><br />For our early elementary kids, I have a sense that it is really valuable for them to interact as much as possible with physical objects rather than always virtual ones. We have done two things to make the construction tools more accessible to them:<br />(1) use a safety compass: this was inadvertent because we bought it along with a set of other things, but it takes away my fear that the compass point will stab someone during their play/exploration. <br />(2) make the whole activity about exploring the tools and building a cool looking picture (including color highlights as desired).<br /><br />They may not be learning how to bisect an angle or construct common tangents to two circles, but they are still building an intuition about what the tools do and something in how they can sequence them to build up complex designs.<br /><br />FWIW, I'm blogging about the (math) games we play with our little ones at <a href="http://3jlearneng.blogspot.com" rel="nofollow">3 J's Learning</a>.<br />Joshua Greenehttp://www.blogger.com/profile/11702319994021721608noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-82545884916930416002014-06-24T07:21:00.253-07:002014-06-24T07:21:00.253-07:00Congratulations, Teach for Life, you win. (What w...Congratulations, Teach for Life, you win. (What we're using is a variation on what you gave us.) You win the signed copy of the book. When it's printed we will send you your prize. Can you send me your email, please? I'm at mathanthologyeditor@gmail.com.Sue VanHattumhttp://www.blogger.com/profile/10237941346154683902noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-60353307805678782802014-06-23T19:39:13.622-07:002014-06-23T19:39:13.622-07:00Hi Rosie, I'm glad you had the game sheet. I s...Hi Rosie, I'm glad you had the game sheet. I see blogspot has lost it somehow. I'll have to fix all the images in my posts after the crowd-funding campaign settles down.Sue VanHattumhttp://www.blogger.com/profile/10237941346154683902noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-12757640324570984252014-06-23T19:07:10.831-07:002014-06-23T19:07:10.831-07:00I played a version of this with my kids today - th...I played a version of this with my kids today - thanks for sharing the idea (I'll have to email you for the gameboard). I threw in a few random things (If you are not wearing socks add x points! If you are wearing red, subtract x points! Add x points for every sibling!) just to keep them from getting too fixed on the competitive aspect of the game... and to keep things a little lighter since it's late June and we are still in school.<br /><br />(@RosieL52)Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-21976332942859114982014-06-14T08:04:14.004-07:002014-06-14T08:04:14.004-07:00The reviews above will be featured on the back cov...The reviews above will be featured on the back cover. Here's more praise for the book.<br /><br />Last year I asked for volunteers to help with the index. Lakshmi was one of them. She wrote me back to say: "I am sorry I have not been able to get to the list of index words. I have not been able to go past the 3rd chapter. I read it three times already. Each time, I sit down and start underlining words, but after a couple of pages I just get so carried away by the book that I forget to mark the words. Having said that, I love the book. It has so many great ideas all in one place."<br /><br />I got plenty of indexable words from the other volunteers, so we were fine. And her comments moved me. I am looking forward to getting the book out there for others like Lakshmi.<br />Sue VanHattumhttp://www.blogger.com/profile/10237941346154683902noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-23148891070570496592014-06-07T00:45:27.847-07:002014-06-07T00:45:27.847-07:00"I found one by starting in the top left corn..."I found one by starting in the top left corner of the 4x4"<br /><br />I meant top right corner.<br /><br />"That did seem odd, didn't it? (More 18s than 16s.)"<br /><br />Yes, I wasn't expecting that, which is why I was mostly focusing on finding more triangles smaller than 18.CMD619http://www.blogger.com/profile/17959687959176018305noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-17336521019862594682014-06-06T21:28:03.341-07:002014-06-06T21:28:03.341-07:00That did seem odd, didn't it? (More 18s than 1...That did seem odd, didn't it? (More 18s than 16s.)Sue VanHattumhttp://www.blogger.com/profile/10237941346154683902noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-68694763634034874402014-06-06T21:24:45.176-07:002014-06-06T21:24:45.176-07:00I finally found the last 4. There were 4 18s I mis...I finally found the last 4. There were 4 18s I missed. I found one by starting in the top left corner of the 4x4, shifting left 1 square, then shifting down 1 square. I forgot to check for this size triangle closer to the center of the 4x4. Also, I didn't think there would be more 18s than 16s since 18s are larger.<br /><br />My final count:<br /><br />64 size 1s<br />64 size 2s<br />48 size 4s<br />36 size 8s<br />24 size 9s<br />12 size 16s<br />16 size 18s<br /> 4 size 32s<br /><br />268 total.CMD619http://www.blogger.com/profile/17959687959176018305noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-77325510908712764752014-06-06T00:51:23.291-07:002014-06-06T00:51:23.291-07:00Ok, I finally found 3 18s facing each direction, b...Ok, I finally found 3 18s facing each direction, bringing my total to 264. Counting all of the triangles in 1x1, 2x2, and 3x3 squares helped me find triangles in the 4x4 I previously missed.<br /><br />My revised count:<br /><br />64 size 1s<br />64 size 2s<br />48 size 4s<br />36 size 8s<br />24 size 9s<br />12 size 16s<br />12 size 18s<br /> 4 size 32s<br /><br />Only 4 more to find!CMD619http://www.blogger.com/profile/17959687959176018305noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-91278226982411533402014-06-06T00:32:17.494-07:002014-06-06T00:32:17.494-07:00Yes, I suppose explaining how you made your formul...Yes, I suppose explaining how you made your formula does serve as a proof.CMD619http://www.blogger.com/profile/17959687959176018305noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-75798966241363638962014-06-05T21:46:23.577-07:002014-06-05T21:46:23.577-07:00Hmm, I didn't write my process out as a proof,...Hmm, I didn't write my process out as a proof, but I feel like I have proved it.Sue VanHattumhttp://www.blogger.com/profile/10237941346154683902noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-37901108541004372552014-06-05T21:44:18.202-07:002014-06-05T21:44:18.202-07:00The math-future (or math 2.0) discussion is here: ...The math-future (or math 2.0) discussion is here: https://groups.google.com/forum/#!topic/mathfuture/W41lMxjhQ1USue VanHattumhttp://www.blogger.com/profile/10237941346154683902noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-36775102977386714092014-06-05T21:20:09.727-07:002014-06-05T21:20:09.727-07:00Yep, it was the rounding. I just entered it as i/2...Yep, it was the rounding. I just entered it as i/2. I didn't understand how to use the round function on the calculator, so I just set it up so that everything gets rounded to the closest integer. From the mode menu I changed the rounding from float to 0. After testing out the rounding, I learned that rational numbers with 5 at the end of the decimal portion are rounded up. So i/2 was still rounded to the next highest integer, but it may not have been the only thing that was rounded. I now understand how to use the round function: first operand is number to be rounded: second operand is number of decimal places. So I set the global rounding setting back to float and replaced i/2 with round(i/2), giving me the result 268. I'm still interested in seeing if I can find the last 8 triangles from examining the 4x4. As far as I know, there is no proof of the formula.CMD619http://www.blogger.com/profile/17959687959176018305noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-55220310205955905162014-06-05T20:17:23.200-07:002014-06-05T20:17:23.200-07:00What did you do with their round(i/2)? They meant ...What did you do with their round(i/2)? They meant the same thing I did with ceiling(i/2), though it's not as obvious with the term round what should happen when you're halfway between two numbers. Unfortunately, I no longer have a TI-84. Perhaps it doesn't do round(i/2) the way the OEIS meant it. (I tried to google it, and couldn't figure it out for sure.) If you use int(i/2+.5), I think you'll get ceiling. int() is the equivalent of floor. (They may act differently on negatives, but that probably depends on what device you're using.)<br /><br />Sue VanHattumhttp://www.blogger.com/profile/10237941346154683902noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-33187890469672663732014-06-05T17:49:54.727-07:002014-06-05T17:49:54.727-07:00I just entered the summation form of the formula g...I just entered the summation form of the formula given on On-line Encyclopedia of Integer Sequences into my calculator (TI-84 plus) for a 4x4, and I got 280, the same answer posted by Cooper Macbeh in the Math 2.0 discussion. But when I enter the closed form I get 268. Why's that?CMD619http://www.blogger.com/profile/17959687959176018305noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-18072618695743862692014-06-05T12:27:53.960-07:002014-06-05T12:27:53.960-07:00Perhaps not as flawed as you're thinking. Each...Perhaps not as flawed as you're thinking. Each time we approach a problem a new way, or another time, it adds to what we've done before. Think of your "flawed" approach as getting to know the problem.Sue VanHattumhttp://www.blogger.com/profile/10237941346154683902noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-17633873270642243872014-06-05T12:13:03.669-07:002014-06-05T12:13:03.669-07:00That's what I've been doing after realizin...That's what I've been doing after realizing how flawed my original approach was.CMD619http://www.blogger.com/profile/17959687959176018305noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-39635236705924842432014-06-05T07:25:19.300-07:002014-06-05T07:25:19.300-07:00Sorry, I threw out my notes when I was cleaning up...Sorry, I threw out my notes when I was cleaning up last night. My recommendation is that you outline one and slowly shift it left or right up or down.Sue VanHattumhttp://www.blogger.com/profile/10237941346154683902noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-8102332102186019562014-06-04T22:21:57.486-07:002014-06-04T22:21:57.486-07:00I just saw that there are three 16s facing each di...I just saw that there are three 16s facing each direction, so 12 total. But I'm still only seeing two 18s facing each corner. Now I've found 260 triangles.CMD619http://www.blogger.com/profile/17959687959176018305noreply@blogger.comtag:blogger.com,1999:blog-5303307482158922565.post-44377195800270623962014-06-04T22:01:56.813-07:002014-06-04T22:01:56.813-07:00I think you missed some 16s and 18s.I think you missed some 16s and 18s.Sue VanHattumhttp://www.blogger.com/profile/10237941346154683902noreply@blogger.com