{"id":5334,"date":"2018-02-28T18:48:15","date_gmt":"2018-03-01T01:48:15","guid":{"rendered":"https:\/\/blogs.ubc.ca\/stem2018\/?p=5334"},"modified":"2018-03-02T07:46:00","modified_gmt":"2018-03-02T14:46:00","slug":"exploring-density-and-buoyancy-with-t-gem-cycles","status":"publish","type":"post","link":"https:\/\/blogs.ubc.ca\/stem2018\/2018\/02\/28\/exploring-density-and-buoyancy-with-t-gem-cycles\/","title":{"rendered":"Exploring Density and Buoyancy with T-GEM Cycles in the Elementary Classroom"},"content":{"rendered":"

It\u2019s been a few years since I\u2019ve taught either Science or Math, and that was to Grades 1-3 most recently, but as I read about GEM and T-GEM I was intrigued and wondered how this model could be applied to primary science. The challenging concept I selected was that of buoyancy and its relationship with gravity\/mass\/density. In Grade 3, students in Ontario study material forces. I recall classes having a hard time understanding why the buoyant force allowed certain objects to seemingly overcome the force of gravity but not others. The concepts of mass, volume, and density are not solidified at this stage so explanations or even demonstrations were not usually deeply understood. If I had an opportunity to teach this Science unit again using T-GEM cycles it might look something like this (over a series of classes, I\u2019m sure):<\/span><\/p>\n

 <\/p>\n

Compile Information <\/b>– I would begin with showing students a data table for five blocks of mystery objects from the <\/span>PHET Density & Buoyancy Simulation<\/span><\/a> and demonstrating how to read a two-column chart. Then we would briefly discuss what students know about these objects, the abbreviations (what does L and kg stand for?) and the numbers beside them (making a connection to money when reading decimals, are these numbers placed in any particular order?). Add keywords to a word wall: litres (L), kilograms (kg).<\/span><\/p>\n

\"\"<\/p>\n

Source: <\/span>https:\/\/phet.colorado.edu\/sims\/density-and-buoyancy\/density_en.html<\/span><\/a><\/p>\n

 <\/p>\n

GEM Cycle 1:<\/b><\/p>\n

Generate<\/b> \u2013 First, I would then ask students to find trends or generate some relationship statements about the data in groups and then share with the class. For example, \u201cThe water has the smallest number but the gold has the largest number\u201d or \u201cI wonder why gasoline is smaller than water? Aren\u2019t they both liquids?\u201d Other questions related to the nature of the data the teacher might guide discussions of include: \u201cWhat might \u201cdensity\u201d be measuring?\u201d, Why is the pool measured as 100 L but the scale measuring 0 kg right now?\u201d<\/span><\/p>\n

Then, I would direct their attention to the cubes and ask them to explain what they see: Each shape is a cube, they\u2019re five different sizes, five different colours, labelled with five different letters. I would ask them to put the cubes in order in two ways (letter label and size) and then to predict what the scale would read if I were to measure each cube. (I would deliberately <\/span>not<\/span> use the term \u201cweigh\u201d or introduce the term \u201cmass\u201d at this point). I would also ask them to predict whether they think any of the numbers on the data table might appear on the kg scale and what whether\/how the 100 L measurement of the pool might change.<\/span><\/p>\n

Then, I would ask students to predict which cube would measure the highest number when I place it on the kilogram scale. (They will likely say the largest cube will be highest and smallest lowest and I will add the word \u201csize\u201d to our word wall). I would ask them write a rule explaining what they think the relationship between a cubes size and how many kilograms it is.<\/span><\/p>\n

 <\/p>\n

Evaluate <\/b>\u2013 Now, I would begin the simulation by placing each cube on the scale and have students (or a student scribe for the class) record the data in a new table:<\/span><\/p>\n\n\n\n\n
Block Label<\/b><\/td>\nSize (1-5, 5=largest)<\/b><\/td>\nKiloGrams (kg)<\/b><\/td>\n<\/tr>\n
<\/td>\n<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

I\u2019m deliberately constraining them at this point by doing this part of the simulation as a demonstration to keep them from dropping the blocks into the pool or changing any of the other variables. I\u2019d ask them to reflect on what they saw: Were your predictions completely correct? How can you explain this? I\u2019d ask them to notice the L measurement change and compare that by measuring the block on the kg scale again and compare these numbers…<\/span><\/p>\n

 <\/p>\n

Modify <\/b>\u2013 Finally, I\u2019d ask the students if their original rule needs to be changed now that they\u2019ve seen the measurements and have their groups try to make a new rule explaining why each block received the measurement it did since it can\u2019t be because of its size.<\/span><\/p>\n

 <\/p>\n

GEM Cycle 2:<\/b><\/p>\n

Generate<\/b> – To start the second cycle, I would ask students to predict what will happen when each block is dropped into the pool and explain their thinking. If they say the same thing will happen to all five blocks (ie. all sink or all float) I would <\/span>not<\/span> correct that at this point. I would ask them to draw what would happen on a two-column drawing one side for \u201cprediction\u201d the other for \u201cactual\u201d. I\u2019d again ask them in their groups to write a \u201crule\u201d for predicting what will happen to a block when it\u2019s dropped into a pool of water.<\/span><\/p>\n

 <\/p>\n

Evaluate <\/b>\u2013 Now, the students would stay in their groups and load the simulation themselves using the Mystery button and experimenting with dropping the blocks into the water, and drawing what actually happened beside their predictions. I\u2019d ask them to reflect on what they saw: Were your predictions completely correct? How can you explain this? <\/span><\/p>\n

 <\/p>\n

Modify <\/b>\u2013 I\u2019d again ask the students if this original rule needs to be changed now that they\u2019ve run the simulation and have their groups try to make a new rule explaining why each block behaved as it did when dropped into the pool and write that down. I\u2019d ask them to record the kg of each block on the \u201cactual\u201d side of their diagrams and consider whether this number might be connected to what they observed in the simulation or not when they make their new rule\u2026?<\/span><\/p>\n

 <\/p>\n

GEM Cycle 3:<\/b><\/p>\n

Generate<\/b> – At this point, I would ask students to predict what will happen when each block is dropped into the pool if the simulation is changed so that all blocks have at least one thing the same, if they all measured the same kilograms for example. I\u2019d again ask them in their groups to write three \u201crules\u201d for predicting what will happen to the blocks that are all the same (a) mass, (b) volume, and (c) density when they\u2019re dropped into a pool of water (it\u2019s not important that they don\u2019t know what they terms mean, this is part of the discovery).<\/span><\/p>\n

 <\/p>\n

Evaluate <\/b>\u2013 Then, the students would stay in their groups and load the simulation themselves and use the \u201csame\u201d x buttons to set the blocks to the same value and continue experimenting with dropping the blocks into the water. I\u2019d ask them to reflect on what they saw and evaluate their predicted rules. I\u2019d assign a role to one of the group members to keep a running record of \u201cthings we want to know\/don\u2019t understand\u201d and to another as the recorder to write or draw the group predictions and rules and the actual results. At the conclusion of this part of the simulations, I\u2019d ask them to come up with a working definition of the terms \u201cmass\u201d, \u201cvolume\u201d, and density\u201d that they\u2019ve been observing.<\/span><\/p>\n

 <\/p>\n

Modify <\/b>\u2013 I\u2019d again ask the students if their original rules needed to be changed now that they\u2019ve run the simulations and have their groups try to make a new rules explaining why each block behaved as it did. I\u2019d challenge them to incorporate their definitions of \u201cmass\u201d and \u201cdensity\u201d into their explanations. <\/span><\/p>\n

 <\/p>\n

GEM Cycle 4:<\/b><\/p>\n

Generate<\/b> – Finally, I would ask students to think about four materials that come in blocks they are familiar with: Ice, Metal, Wood, and Styrofoam. I would ask them to explain to me what would happen if I threw a block with the same mass but of each different material into the pool. (I might bring in these objects and a bowl to help them imagine). I would then return to the Mystery simulation screen and reveal to them that the blocks in this simulation are each made of a different mystery material just like my example objects. I would ask them to generate a rule using material names for what would happen when we dropped those materials into a pool.<\/span><\/p>\n

 <\/p>\n

Evaluate <\/b>\u2013 So now, the students would stay in their groups and load the simulation but go to the Custom button. I\u2019d ask them to experiment with the different materials, their masses and volumes and explore\/record\/discuss what happens. <\/span><\/p>\n

 <\/p>\n

Modify <\/b>\u2013 I\u2019d ask the groups to use this information to try to identify the material of each mystery block using the data from all the simulation tabs. As an extension, I\u2019d introduce the <\/span>Buoyancy Simulation<\/span><\/a> (Intro tab only) and allow them to gather information to inform their hypothesis from those materials and we\u2019d discuss the concept of weight (N) versus mass (kg) at this point, while formally introducing the topic of the buoyant force. \u00a0Finally, we\u2019d return to the data table from the first cycle and ask students to explain what it means that wood has a density of 0.40 kg\/L while lead and gold (both metals) have a much higher density. What would happen when we drop wood into the pool versus metal? Then in the Buoyancy Playground tab of that simulation, they\u2019d compare materials such as styrofoam, wood, or metal and craft a final truth statement about gravity (N or kg) and density as well as density and buoyancy.<\/span><\/p>\n

 <\/p>\n

Extensi<\/b>on\/Next Steps<\/b> – I\u2019d draw their attention to the bottom of both tabs in the Buoyancy Simulations where the density of the fluid within the pool can be changed and observe what happens to the blocks when the fluid is converted to \u201cair\u201d \u201cgasoline\u201d \u201colive oil\u201d \u201cwater\u201d or \u201choney\u201d.<\/span><\/p>\n

 <\/p>\n

Have you used GEM cycles in Primary Science or Math in your practice? \u00a0I’d be interested in how that went in terms of student understanding, management, and time.<\/p>\n","protected":false},"excerpt":{"rendered":"

It\u2019s been a few years since I\u2019ve taught either Science or Math, and that was to Grades 1-3 most recently, but as I read about GEM and T-GEM I was intrigued and wondered how this model could be applied to primary science. The challenging concept I selected was that of buoyancy and its relationship with […]<\/p>\n","protected":false},"author":51923,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1669392],"tags":[],"class_list":["post-5334","post","type-post","status-publish","format-standard","hentry","category-b-t-gem"],"_links":{"self":[{"href":"https:\/\/blogs.ubc.ca\/stem2018\/wp-json\/wp\/v2\/posts\/5334","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.ubc.ca\/stem2018\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.ubc.ca\/stem2018\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.ubc.ca\/stem2018\/wp-json\/wp\/v2\/users\/51923"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.ubc.ca\/stem2018\/wp-json\/wp\/v2\/comments?post=5334"}],"version-history":[{"count":3,"href":"https:\/\/blogs.ubc.ca\/stem2018\/wp-json\/wp\/v2\/posts\/5334\/revisions"}],"predecessor-version":[{"id":5389,"href":"https:\/\/blogs.ubc.ca\/stem2018\/wp-json\/wp\/v2\/posts\/5334\/revisions\/5389"}],"wp:attachment":[{"href":"https:\/\/blogs.ubc.ca\/stem2018\/wp-json\/wp\/v2\/media?parent=5334"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.ubc.ca\/stem2018\/wp-json\/wp\/v2\/categories?post=5334"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.ubc.ca\/stem2018\/wp-json\/wp\/v2\/tags?post=5334"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}