## Do your students know what a group is? or what a group of ten is?

I’ve been wanting to incorporate counting collections at school for a while, but I haven’t had the understanding of how to organize counting collections effectively. I recently attended a colleague visit where a kindergarten teacher showed the procedures she used for teaching counting collections. So, after attending this training, I initiated counting collections at our school with the 1st and kindergarten teachers. In the meantime, one of the kindergarten teachers shared with me at school that she realized her students didn’t know what a group was– much less know what a group of ten was. She began her instruction with just discussing groups and what kinds of things can come in groups. They talked about groups of three, four, or six etc. They made groups of different amounts in whole group discussion under the document camera. Students were able to have a foundation to understand a “group of ten.” Then the teacher was able to place a different amount of counters underneath the camera to ask if she had a group of ten. First, she placed less counters under the camera like 8 and asked if she had a group of ten. After that she placed more counters under the camera, like a group of ten and 3 more, and asked if she had a group of ten. Doing all of these seemingly common sense-ical counting procedures before hand led to a much more successful counting collections lesson for students to count their collections effectively. These are the rudimentary things that no college or textbook teaches you!

To read the valuable counting collections article from Teaching Children Mathematics, click here.

## Use This Simple Idea to Make Patterns Explicit in Number Charts

When having second grade students explore patterns in number charts which were in increments of 300, it dawned on me to cover up some of the numbers to show students how the numbers repeated. I did this on the document camera. For those students who weren’t able to see the number patterns explicitly, this proved to be very helpful.

The number chart is shown above uncovered.

First, I left one column uncovered except for the hundreds place. Students were easily able to see how the hundreds place repeated.

Then I uncovered all but the tens place. Students saw that the tens place goes up by one ten going down each row.

Finally, I uncovered all except the ones place and students were able to see that the ones place remained the same ALL the way down the chart.

In case you are interested, these number chart printables to 1,200 are available here. There are fill in number charts too.

Smart Board lessons that match the printables are available here which may work even better for showing the patterns with the screen shade.

## If a Student Can Build 199 with Base Ten Blocks, Can They Count to 199?

Another base ten realization occurred to me today! Working with one of my intervention groups I had them build the number 199. I initially had the intention for them to add one more unit after they had counted to 199 for them to cross a century. This would make the number 200. While working with the students in the group, only *half* of them* could actually count* the number they had built. Then I realized that students can easily build a number with blocks recognizing the pattern of hundreds, tens, and ones without actually understanding the number they have built.

While I know it may take a while, I suggest that while students are building or representing base ten blocks that students actually show their counting numbers underneath, which I had never thought to make students do before. I had always taken for granted that students understood the counting numbers if they could build the numbers with blocks, but this regretfully isn’t always the case.

## Could the Thousands Blocks in Your Classroom Be Causing a Misconception?

Students who struggle with number sense aren’t sure how many 10’s are in 100, how many 100’s are in 1000 and so on. Because of this I work on this skill often with students in my intervention groups. On more than one occasion, I have found that students even as old as fifth grade have a misconception about the thousands block. Now that we have math tools made from plastic instead of the vintage wood ones, some students are confused when they lift the thousands block. They realize the plastic thousands block is hollow, so when I ask them how many hundreds are in a thousand, they count the sides and say six. I have to correct them and have them just stack the hundreds blocks until they are the same size. Then they realize that 10 hundreds make 1000.

## Are Your Students Struggling with Ordering Decimals…Try This!

To help 5th graders understand decimals last week, I built this number line using an old roll of fax machine paper. I measured off a little over two meters and then marked every two centimeters to put another number, so I would have room to write the numbers and for them to actually be seen. Students don’t usually have much of a problem ordering decimals to the hundredths place because they can visualize pennies and dimes, but past that students struggle. Also, thousandths are a bit daunting to teach…after all they don’t make “thousandths” manipulatives….at least that I am aware of. This coming week, students are going to build their own number line between two hundredths and we are going to connect all of the number lines and put them somewhere…I am not sure where because it will be VERY LONG because 100 numbers are written on it. Another something I did to the number line is I glued hundredths blocks down underneath the hundredths numbers, so students could see the concrete representation of these.

In case you aren’t familiar in decimal base ten block world:

a flat = 1 whole

a rod = 1 tenth

a unit= 1 hundredth

When explaining hundredths and thousandths to students I do the unthinkable. I take a blue foam base tenth block and a pair of scissors in front of the class and *SNIP* a hundredth goes flying a few feet away. This grabs students attention because #1, I just cut a holy math manipulative, and #2 something just went flying across the room for those students who may have just momentarily zoned out . No worries, I have had tubs and tubs of these math manipulatives (oh we are calling them “tools” now) that I could build a shrine to them with lit candles. In other words I have plenty that if I cut one it isn’t a big deal. THEN, I take the itty bitty hundredth that I just cut and *SNIP* another slice goes flying. I tell students that this slice is one thousandth. This visual really helps students to see how tenths, hundredths, and thousandths are related. A speck can even be cut off of the thousandth so that students can see what a ten thousandth looks like. After I have cut all of these pieces off, I put them underneath the document camera so students can see them up close.

Update 4-11-2019 Since this post has become so popular, I am going to list the number line I made that is like the base ten block one above , but it is all nice and printable.

## To Teach or Not to Teach the Cent Sign?

I love it when I’m right. The other day I was having a friendly debate with another teacher about whether or not to teach the cent sign with the new common core standards. After all, sometimes students use the dollar sign at the same time along with the decimal point and get them confused. I argued, however, that you still see the cent sign at times in stores , but this person argued that you don’t see the cent sign anymore…well, here you go…the cent sign at back to school time! Seventeen cents for a spiral bound notebook. My proof that IT IS STILL IN USE, so we still need to teach students how to read them!

I’ll let you in on my little secret. Now beware it is a little simple and silly, but kids love silly and so my story works.

The cent sign at one time was the dollar sign’s girlfriend, but they broke up. Then the dollar sign and the decimal point got married, so they are seen together almost always. The cent sign got her feelings hurt when the dollar sign got married to the decimal, and so she ran away. THE END.

Adapt and embellish the story to fit your personal style. Now just remind your kids of this story any time they get confused about the notation of dollars and cents, and they will remember which sign to use.

## Use Your “Time” Wisely doing this…

Never take your blank classroom wall space for granted. Below I have pictured what I placed around my classroom clock. Then I added some extra items instead of just the numbers around the clock with the quarters of an hour as I saw students having misconceptions about several concepts. I noticed students struggling with all of the different words that meant before (to, til, until), so I posted an anchor chart showing this around the clock. I also posted an anchor chart showing how each fifteen minute increment adds up as quarters of an hour. This is a picture from a classroom I had several years ago, and it isn’t the most beautiful, perfect clock display. If you use this idea or have done something similar, post a link in the comments to show how you displayed yours in a more aesthetically pleasing way since mine is lacking in this department :).

## I Just Saw the Most Brilliant Use of a Flip Cam!

When I stepped into a classroom yesterday I was so intrigued that I couldn’t leave. Before I spill the beans on what I saw, I must say this. There has been a lot of emphasis at my school about having students share their work for a lesson closing. This idea could also spill over into the common core mathematical practices in which students must “construct viable arguments and construct the reasoning of others”. Now I understand that when students share their work in front of the class that this does promote other students’ higher levels of thinking as other students decide whether they agree or disagree. On the other hand at this late point in the school year the downfall of student sharing is that even with a doc camera and students’ micro phoned voices other students attention spans are likened to a fly hovering over a summer picnic buffet.

Now, onto what I saw. Ms. T was showing students a flip cam video of herself talking to a student named ‘Briana’, who was solving a double digit addition problem with base ten blocks which she had taped during the students’ work time. She showed the video to students after their work time and paused it after the questions she asked Briana in the video. Then Ms. T would ask the class what the answer was to the question in the video. The class would respond. Then Ms. T would un-pause the video to allow the class to see if Briana answered, counted, or exchanged blocks correctly. I absolutely loved this–so much more engaging than regular sharing!

Thanks to the literacy people who ordered these flip cams with literacy money! 🙂 They were originally bought for students to do book talks. Using them for math sharing–so much better in my unbiased opinion ;).

## Are You Teaching Branching? Make Sure You Do This First…

Several years ago I worked at a charter school the first year it opened. The school implemented Singapore math, so that was my first year to test the waters of Singapore math. Our trainer instructed the 3rd grade teachers to go ahead and teach branching even though it was a skill the students should have learned in second grade. To teach children the procedure of branching, it took about four weeks total, and then not all of the students perfected the ‘procedure’ of addition and subtraction branching. The students had more success learning addition than subtraction branching. With the mandates of testing, we weren’t able to solely use Singapore math, but I had to supplement with other materials. Then as you are all familiar with, testing approached and likewise the pressure along with it. Then we didn’t have ‘time’ to teach number sense SO deeply since other skills are tested. Unsurprisingly, the teaching of Singapore Math somewhat fell apart midyear. Please don’t take this wrong I LOVE Singapore math because it works, but the conditions of testing hindered us from teaching it wholly.

Fast forward to four years later. After teaching small groups today, I have reflected on the year that I taught branching and its effectiveness. Yesterday I pulled small groups of average math students to teach them regrouping for the second day in a row, I had them build double digit numbers with base ten blocks blocks. I repeated this process today with the same group of students. After that I started notating their thinking with branching representation on a small white board. Students intently watched and helped me notate the thinking they had done with the blocks in (abstract) numbers . They began to understand grouping with tens and how to decompose numbers to build more tens or hundreds. Then I told them that they couldn’t use paper or blocks, but could only look at the addends I was about to write on the board. I asked them to whisper the answer in my ear so that others could still think. I was amazed! Half of them could answer the question correctly doing mental math. The other half were only 1 away from the correct answer. I was so proud.

I shared the above to really say the kids taught me something in just two days because of their adept ability to add mentally. Teaching branching worked so much better four years later–all I had to do was provide an experience with branching directly after building with base ten blocks. Why didn’t I **start out with the concrete blocks first before I threw abstract numbers at them**…duh me! Branching made so much more sense to them after building a concrete foundation. Reflection is priceless!

## Do Your Kids Need a Dawning Division Moment?

After sitting in a week’s worth of meetings about Common Core instruction and best math practices, I feel as if my way of instructing students is gradually morphing into a new beast, which I am not sure I fully can describe yet. In the midst of all of this, I went back to the fifth graders I have been working with on the day after these meetings. I decided to try out some of the teacher practices I had been learning. Sidenote: This set of fifth graders isn’t yet proficient at long division or ladder division for that matter. I posed a long division problem to the students, but instead of giving it to them in “naked numbers” alone, I gave it to them in word problem form as well. In reflecting, I should have started out with the word problem alone and let the students figure out that they were supposed to divide. After watching the students struggle with solving using ladder division or the traditional long division algorithm, I encouraged the students make equal groups to see if that helped them. One student in particular that I worked closely with (whose work is pictured below) managed to find a correct answer using equal grouping, however he could not find his mistake when he used ladder division. Another student…one I might add who typically doesn’t have much perseverance to solve problems…related completely to the contextual situation and persevered through to solve the problem to the end. To get to my MAJOR DIVISION REVELATION, let’s look at this student work below:

So, you ask, what is the big AH-HA? If you notice that the numbers in the student’s circles (equal groups) are the same numbers to the side of the division problem (or the ladder). The numbers to the side of the ladder are actually the chunks that students would naturally break off if they were naturally dividing cookies among people etc.! Now I know according to my PD classes that I shouldn’t have just *told and shown *the student this relationship, but I should have allowed him to figure it out. I was just a little too excited to hold in my own personal discovery I suppose.

Another discovery I had in experimenting with having students discover their own strategies, I learned that students * actually do* better and persevere more when the problem is in a context familiar to them and it isn’t just a naked numbers problem. Having a contextual situation actually gives the students an entry point into the problem, and so they don’t give up as quickly. I have always thought backwards. Students MUST UNDERSTAND THE NAKED NUMBERS FIRST and THEN they can SOLVE HARD WORD PROBLEMS.

**But in reality**after my experiment with these fifth graders,

**they were much better at solving this division problem in their own way when they had a context**. I have had a complete paradigm shift, and you were all here to see it above– that is.