Comparing the Accuracy of Liquid Measurement Tools

Blog, She Wrote: Comparing the Accuracy of Liquid Measurement Tools

Have you ever thought about how accurate your volumetric measuring tools are? How do you know your measuring cup is calibrated? Is it good science to use your kitchen tools for science? Today’s discussion is Comparing the Accuracy of Liquid Measuring Tools.

Are All Volumetric Measuring Tools the Same?

Blog, She Wrote: Comparing the Accuracy of Liquid Measurement Tools

The gold standard in measuring volume is the Volumetric Flask. It’s a laboratory flask which is calibrated precisely to a certain volume at a particular temperature. They come in various sizes from 1-10,000 mL of liquid. But, they are also expensive and they are typically not found in classroom labs or homes because neither work with extremely precise volumes of liquid.

So, what do we use instead? The rule of thumb is to use the graduated cylinder. With all the markings on the cylinder, it is considered more accurate than other volume measuring tools. But, is there a big difference? We decided to test them to see.

Tools for Measuring Volume

Blog, She Wrote: Comparing the Accuracy of Liquid Measurement Tools

What are some tools available for measuring volume?

  • Beakers- Are containers primarily used for mixing and heating. There are markings on them for measuring, but they are meant to be approximate.
  • Measuring Cups- The liquid measuring kitchen variety. We use Pyrex brand.
  • Erlenmeyer Flasks- These are wide bottomed but not circular with a neck that can use a stopper (with or without holes). It makes a good reaction vessel and allows a larger area for smaller volumes.
  • Florence Flask- This is a round bottomed flask used for boiling solutions.
  • Field Collecting Tubes- These are screw top collecting tubes which come in 15 mL or 50 mL and they are terrific for collecting aquatic specimens in the field. We use them during our entomology excursions.
  • Pipettes- Used for moving small volumes of water or removing liquid in small increments. I like the disposable kind because the cleaning is much easier!
  • Graduated Cylinder- Are used for measuring volumetric quantities. They range in size from 10- 1000 mL. If you are going to choose only one, the 100 mL size is a good one.

So, if you want to use something other than what’s found in your kitchen, where do you get them? We use Home Science Tools. We order some specialty items, like collecting tubes, from BioQuip. Just for fun, we also visited our local university’s chemistry supply room. Armed with gift money, our then 8 year old, took a trip with Dad to pick out his own glassware.

Testing the Accuracy of Volume Measuring Tools

Blog, She Wrote: Comparing the Accuracy of Liquid Measurement Tools

Since we used the graduated cylinder as our gold standard, we chose to determine the final volume in a graduated cylinder. Our procedure:

  • Choose a beaker, flask, or collecting tube and fill it with water to the highest marked volume in mL.
  • Record that volume in your data chart which will be labeled with the containers you are using.
  • Pour the contents of the first container into the appropriately (closest) sized graduated cylinder available.
  • Measure the volume of water in the graduated cylinder
  • Record the volume.
  • Repeat using various sized measurement tools.

How to Record Data When Doing a Science Exploration

Blog, She Wrote: Comparing the Accuracy of Liquid Measurement Tools

The data chart for recording volume was designed by each student separately based on what we needed to write down. Here are a few things to remember about data charts and recording data.

  • Have each student design her own based on ability- parents can step in when columns are missing.
  • Give hints or general categories students need to remember when constructing their own chart. It’s ok if the charts turn out differently from others as long as they record everything.
  • Creating their own data chart is a great way to learn the skill of organizing information. I think we underestimate the importance of our homeschooled students being able to organize information on their own- without the help of a printable!
  • Remember printables are fun, but they aren’t necessary and sometimes they slow you down- like when you are spending all your time looking for ones you’ve already printed or when you can’t find just the perfect one.
  • Scientists in the field must create their own data charts since they often design their own experiments. Step boldly!

Our Findings- How Accurate are the Volumetric Tools?

Blog, She Wrote: Comparing the Accuracy of Liquid Measurement Tools

What were the results?

  • All volumetric containers are not the same!
  • The graduated cylinder has more markings and measures more accurately – it was certainly easier to determine an accurate volume with more gradations.
  • The readings on the graduated cylinder were higher than the same volume measurement in the other tools.
  • The larger the container, the larger the discrepancy. The largest beaker was off my 20 mL or more!

What does it all mean? Well, it means if you want accurate volume without using a volumetric flask, use the graduated cylinder for the best results. Always use the container that will reasonably hold your liquids. If you use the extreme opposite, your readings will be less accurate.

Does My Homeschool Need Volumetric Measuring Tools?

Some of you might be asking whether or not it’s a good idea to invest in some volumetric containers for your homeschool. Is it a good idea? Here are a few things to think on:

  • Using containers meant for science frees up your kitchen tools- I prefer to use science tools for science and kitchen tools for the kitchen. That might be the science teacher talking, but it’s more than that!
  • Some chemicals don’t belong in vessels we eat from- Perhaps your wet labs aren’t dangerous, but some of them might be.
  • Using science tools reinforces safety measures- We don’t eat in the lab! Nor should we really eat from vessels used in the lab.
  • Ensures your students know how to measure volume accurately using appropriate tools
  • Your students will be versed in labware and how to use it
  • It helps our science to be more accurate- rather than guessing at volume when your liquid falls somewhere between 50 mL marks!

It’s easy to start out with a few beakers and graduated cylinders. We have a mixture of plastic and glass, but plastic lets me relax a little more. I would recommend a 100 mL graduated cylinder, 250 & 500 mL beakers at a minimum to start. If you work in small volumes, a 10 mL graduated cylinder is a good size.

Even the simplest of labs can introduce a great deal of concepts and provide plenty of practice at homeschool science. It’s important to use scientific volumetric tools as much as possible. Your measurements will be more accurate!

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Benefits of Using LEGO Mindstorms in Your Homeschool

Blog, She Wrote: Benefits of Using LEGO Mindstorms in Your Homeschool

Welcome to blog sponsor Explorental!

Have you ever considered a LEGO Mindstorms kit for your kids? Maybe you’ve seen them, but are unsure whether the investment is a good one for your family. For less than the cost of a popular game console system, you can have a tool for teaching endless concepts and a source of engineering challenge for your kids.

Reasons to Use LEGO Mindstorms in Your Homeschool

Working with the Mindstorms kit requires a lot of different skills from students even when you are just starting out. Take a look at some of the subject areas accessed by work with the Mindstorms.

  • Math- Although not always a student favorite, math is applied to the robot building when it comes to programming it. Geometry, particularly circle geometry is necessary to accurately get the robot to rotate the wheels the requested distance.
  • Robotics- Who doesn’t want to build a robot and take over the world? Or at least the LEGO world!
  • Mechanics- Part of the robot building has to do with putting the robot together with the technic pieces. How those fit together and work efficiently is a big part of the task.
  • Physics- Along with efficiency, you need a stable structure. We spend a lot of time learning about which designs are the most stable.
  • Fun- There is no shortage of fun when it comes to exploring with a LEGO Mindstorms kit.

Blog, She Wrote: Benefits of Using LEGO Mindstorms in Your Homeschool

Using Technology in Your Homeschool

Our kids use a lot of technology in our home- whether it’s a Kindle eReader, tablet or computers for programming and playing. One thing we really try to keep in check is how much our children are producers vs consumers when using technology. In other words, are they watching a lot and engaging in passive participation or are they being makers and creators?

LEGO Mindstorms uses software that is drag and drop so you only need to know some basics about how to get the robot to follow your commands. It takes time to master, but it’s worth the end result. I don’t mind my kids toiling for a few hours at a computer if they are actively problem solving. 

Enjoy a look at Ethan (and our basement!), our 15yo 10th grader, explaining one task he and his fellow FIRST LEGO League team members completed for their FLL regional competition in December. Our teams spend 7 hours a week pouring into this particular piece of technology and it earned them Grand Champion at their qualifying tournament.

Teaching with Technology G+ Hangout

Last week the iHN hosted an informative G+ Hangout on Teaching with Technology. I was excited to be one of the participants. Click and view at your leisure to hear how others are using technology in their homes.

Using Explorental to Experience LEGO Mindstorms

LEGO Mindstorms is a wonderful resource for homeschools, but it may not be the right time financially to invest in your own. How do you get a chance to work with the kit without making that big financial investment?

Take advantage of Explorental’s wonderful inventory of technology gadgets and other kits. They offer a LEGO Mindstorms rental for $43.99 for two weeks.

Blog, She Wrote: Explorental

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Homeschooling Middle & High School Math

Blog, She Wrote: Homeschooling Middle & High School Math

Today’s iHomeschool Network Hopscotch topic is math instruction. At the middle and high school level we are all about problem solving- taking basic skills and applying them to a problem whether the problem is higher level math like trigonometry or a practical issue like building a project or creating a pattern.

Strategies for Teaching Middle & High School Math in Our Homeschool

  • LEGO NXT- programming and using the LEGO Mindstorms kit to perform tasks. Our family is a FIRST LEGO League family, but at home our NXT kits get a lot of use
  • Computer programming- With online programs such as Scratch and Alice, we can broaden our students’ experience with computer programming. Our 8yo actually program simple commands in C++ and is working his way through a book on Java.
  • Games- We are still a family of game players. Playing fun games that require spatial reasoning or simply hardcore calculations is a fun diversion. Equate is a math crossword game that goes way beyond Smath.
  • The Crafty Side of Math- A big part of our 8th grader’s homeschool is her sewing. She will work out math as she needs it in her sewing and works hard to see a problem get solved. Two links to explore sewing math: The Making of a Wizard & The Crafty Side of Math and Jules Verne- R13 is making a fabulous steampunk gown for her American Girl dolls. Keep in mind that R13 drafts her own patterns and designs her own apparel.
  • Test Prep- I can hardly believe we are at the point where Ethan is practicing his test taking skills for the PSAT. He has practiced in a mock testing situation twice and we’ve been going over things at home.
  • Applied Math- Need more ideas? Try some from the list I made for Uzinggo.

Blog, She Wrote: Homeschooling Middle & High School Math

What about Upper Level Math in Your Homeschool

Probably one of the main concerns of homeschooling parents is how to handle high school math when they don’t consider math their strong suit. We tackle this in a few ways.

  • First, the curriculum we use is written to the student. So, the first pass at the concept is from the text.
  • They try out the problems and check their own answers. If they get stuck, we’ve got a few options.
  • I help them sit and take another look at the problem- I’ve had math through Calculus, but I am not an expert. However, I am successful at helping our kids to look through a problem and see where to go next. I can often look at their work and see where they strayed in their process. This helps them to get back on track.
  • Reteach- if they really are struggling, I take some hints from my Math on the Level manual and teach the concept in a different way. I rarely have to do this, but when I do it helps a lot. Of course, once we enter high school math MOTL is not the go to resource. It works very well for middle school math.
  • Dad can save the day! Dan is an engineer and he is confident in his math abilities. He steps in when the kids are really stuck.
  • Kahn Academy & Uzinggo- We also pull from online tutorials to get back on track or to have something explained in a different way than their textbook offers.

Our Favorite Middle & High School Homeschool Math Curriculum

Blog, She Wrote: Homeschooling Middle & High School Math

  • Math on the Level- A lovely living math approach which allows you to teach math concepts when your student is ready not when a publisher tells you to do so. This one goes from Pre-K through 8th grade pre-algebra. I have a detailed post on how we use Math on the Level in our homeschool. It’s a home base where even I can check on a concept before teaching them to my kids.
  • Life of Fred- Our primary math program for high school is Life of Fred. I get a lot of questions about this and you can read about our decision to use Fred and how it’s a fit for our family by clicking on that link. It’s one of my top 3 posts here at Blog, She Wrote.
  • Family Math: The Middle School Years- Love this book for fun, practical, hands-on activities for middle schoolers. There is plenty in this book to help students with algebraic concepts. I can’t believe this one is out of print, but I cannot find it on Amazon.
  • Yummy Math- This is one of my favorite sites for picking up instructional packets on applied math. You’ll see a math activity which applies to any number of everyday/headline type stuff. There is an endless supply of applied math activities devoted to middle school students.

Blog, She Wrote: Teaching Middle School & High School Math

Join other bloggers in the iHomeschool Network for a look at teaching math in your homeschool. You’ll see how moms of gifted and special needs children approach math at home.

HopscotchiHNJanuary2013

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