Cell size and scale

Just a neat link my hubby found this morning...

http://learn.genetics.utah.edu/content/begin/cells/scale/

You can zoom in to see these various things starting from a coffee bean and down to a skin cell, human egg, red blood cell, bacteria, viruses, hemoglobin, glucose and molecules, etc., all the way "down" to a carbon atom.

In measuring scale, you go from millimeters (0.001 or 10^-3m) to micrometers (0.000001 or 10^-6m) to nanometers (0.000000001 or 10^-9m) to picometers (0.000000000001 or 10^-12m).

Cell size and scale

Just a neat link my hubby found this morning...

http://learn.genetics.utah.edu/content/begin/cells/scale/

You can zoom in to see these various things starting from a coffee bean and down to a skin cell, human egg, red blood cell, bacteria, viruses, hemoglobin, glucose and molecules, etc., all the way "down" to a carbon atom.

In measuring scale, you go from millimeters (0.001 or 10^-3m) to micrometers (0.000001 or 10^-6m) to nanometers (0.000000001 or 10^-9m) to picometers (0.000000000001 or 10^-12m).

10/10 and the Metric Week

Photo courtesy of Miss Colleen

Today is 10th of October or 10/10. As we know, the metric system is based on number 10. Thus, the week ending today has been designated as the metric week..

The National Council of Teachers of Mathematics (NCTM) started the National Metric Week tradition in 1976. Please read a little bit more about the history of the Metric Week here.

You could celebrate the Metric Week doing some metric units puzzles and quizzes. Here's a link to postal stamps and cards celebrating the metric system.

NCTM has tons of related resources so I'll mainly point you there.

I grew up using the metric system, and so I've actually had to learn the imperial system while authoring math materials. These days, it seems, I know the U.S. system better than the people around me... But the metric is sure easier, as far as calculations and conversions go, since you just have to remember it goes by 10s.

In fact, to fully operate in this world, it seems it's best to know both.

Converting between metric and U.S. measuring systems

Here are a few helpful guidelines if you find yourself having to switch between one or the other. I have these conversion factors memorized from much of use. Not that everyone else would actually use these all as much as I do, being in the business of authoring math materials, but anyway:

1 quart ≈ 1 liter, but 1 quart is slightly less.
1 liquid ounce ≈ 30 ml. From this, one can figure out that 1 cup ≈ 240 ml and 4 C ≈ 960 ml.

1 inch = 2.54 cm
It's an awkward number but I need to use this conversion factor constantly, when working with images on my computer, which has a resolution of 96 pixels per inch... but I need the image to print out as 5 cm long or whatever.
You could use 1 inch ≈ 2.5 cm.

Another way is to think about those typical student rulers which are 12 inches = 30 cm. So... 4 inches is 10 cm.

Also... 1 inch might very well be the length of your thumb's last bone (the bone that contains the nail). Check! And 1 cm might very well be the width of any of the other fingernails. Check!

1 yard ≈ 1 meter; better yet 1 yard ≈ 90 cm and 1 meter = 100 cm. You see, that student ruler was 12 inches = 1 foot ≈ 30 cm.

1 mile ≈ 1.6 km. Or, 5,000 meters or 5 K is a popular running distance... about 3 miles.

1 pound is about 450 g, but actually it's easier to remember 1 kg = 2.2 lb.

It's fairly easy to multiply by 2.2. I have a metric scale; I might weigh about 55 kg. 55 x 2 = 110 and 55 x 0.2 = 11. So I weigh about 121 lb.

And 1 ounce ≈ 30 g. Just like 1 liquid ounce was about 30 ml.

To convert anything, go to Google and type

25 lb to kg
8 m to inches
22 km to miles
etc.

10/10 and the Metric Week

Photo courtesy of Miss Colleen

Today is 10th of October or 10/10. As we know, the metric system is based on number 10. Thus, the week ending today has been designated as the metric week..

The National Council of Teachers of Mathematics (NCTM) started the National Metric Week tradition in 1976. Please read a little bit more about the history of the Metric Week here.

You could celebrate the Metric Week doing some metric units puzzles and quizzes. Here's a link to postal stamps and cards celebrating the metric system.

NCTM has tons of related resources so I'll mainly point you there.

I grew up using the metric system, and so I've actually had to learn the imperial system while authoring math materials. These days, it seems, I know the U.S. system better than the people around me... But the metric is sure easier, as far as calculations and conversions go, since you just have to remember it goes by 10s.

In fact, to fully operate in this world, it seems it's best to know both.

Converting between metric and U.S. measuring systems

Here are a few helpful guidelines if you find yourself having to switch between one or the other. I have these conversion factors memorized from much of use. Not that everyone else would actually use these all as much as I do, being in the business of authoring math materials, but anyway:

1 quart ≈ 1 liter, but 1 quart is slightly less.
1 liquid ounce ≈ 30 ml. From this, one can figure out that 1 cup ≈ 240 ml and 4 C ≈ 960 ml.

1 inch = 2.54 cm
It's an awkward number but I need to use this conversion factor constantly, when working with images on my computer, which has a resolution of 96 pixels per inch... but I need the image to print out as 5 cm long or whatever.
You could use 1 inch ≈ 2.5 cm.

Another way is to think about those typical student rulers which are 12 inches = 30 cm. So... 4 inches is 10 cm.

Also... 1 inch might very well be the length of your thumb's last bone (the bone that contains the nail). Check! And 1 cm might very well be the width of any of the other fingernails. Check!

1 yard ≈ 1 meter; better yet 1 yard ≈ 90 cm and 1 meter = 100 cm. You see, that student ruler was 12 inches = 1 foot ≈ 30 cm.

1 mile ≈ 1.6 km. Or, 5,000 meters or 5 K is a popular running distance... about 3 miles.

1 pound is about 450 g, but actually it's easier to remember 1 kg = 2.2 lb.

It's fairly easy to multiply by 2.2. I have a metric scale; I might weigh about 55 kg. 55 x 2 = 110 and 55 x 0.2 = 11. So I weigh about 121 lb.

And 1 ounce ≈ 30 g. Just like 1 liquid ounce was about 30 ml.

To convert anything, go to Google and type

25 lb to kg
8 m to inches
22 km to miles
etc.

Measuring worksheets

I finally got around to creating another worksheet generator that had been "lacking" for a while from my "collection" - measuring units worksheets. Those where you ask kids to convert 6 cups to ounces, or 5 kg 40 g to grams.

Measuring units worksheets

These are free and printable. I've made lots of ready-made links for some common type worksheets, but of course with the generator you can customize it how you want. Both metric and customary units are included; however I did not include all possible metric units, because the focus here is for grades 3, 4, and 5.

Measuring worksheets

I finally got around to creating another worksheet generator that had been "lacking" for a while from my "collection" - measuring units worksheets. Those where you ask kids to convert 6 cups to ounces, or 5 kg 40 g to grams.

Measuring units worksheets

These are free and printable. I've made lots of ready-made links for some common type worksheets, but of course with the generator you can customize it how you want. Both metric and customary units are included; however I did not include all possible metric units, because the focus here is for grades 3, 4, and 5.

Conversion chart for measuring units

I was just sent a link to this site; all it is, is a handy one-page printable conversion chart for various US measures, metric measures, and US vs. metric measures. Includes even a comparative Fahrenheit vs. Celsius thermometer.

http://metricconversioncharts.org/

Conversion chart for measuring units

I was just sent a link to this site; all it is, is a handy one-page printable conversion chart for various US measures, metric measures, and US vs. metric measures. Includes even a comparative Fahrenheit vs. Celsius thermometer.

http://metricconversioncharts.org/

Measure the circumference of the earth - contest

I got word of an interesting contest where school children will form teams and attempt to measure the circumference of the Earth using the same method as Eratosthenes used back in ancient times.

Any students from USA, Mexico, and Peru can form these teams, whether homeschooled, after-schooled, public schooled or whatever.

Whether you will participate or not, go see the animation that explains the method Eratosthenes used (in the left sidebar).

This sounds like an exciting opportunity to connect geometry, measuring, and math history in a project!

And here's some more information:

---

Please help us get the word out on this new, exciting student centered event!

Measure Your World!

Join us this fall as we pilot a new student-centered project where teams from the United States, Chile, and Mexico partner to replicate the technique introduced by Eratosthenes to determine the circumference of the Earth. Around 240 BC, Eratosthenes used trigonometry and knowledge of the angle of elevation of the Sun at noon in Alexandria and in Syene to calculate the size of the Earth. Windows to the Universe, Educared, and CREA are working together to offer school children in the U.S., Chile, and Mexico the opportunity to form partnerships, take local measurements, and collaborate using the Eratosthenes method to Measure Your World.

All of the information necessary to participate in this pilot student project can be found on the Measure Your World Web sites (www.measureyourworld.org and www.MideTuMundo.org). Student teams must have a parent or adult sponsor to participate. At least one of the team members or adult sponsors must be fluent in both English and Spanish. This event is open to all students in the three participating countries and does not have to be affiliated with a formal K-12 school. Home-schooled children and children participating in after-school programs (e.g. the Scouts, 4-H, etc.) are welcome to participate.

In addition to taking the measurements and calculating the circumference of the Earth, student teams will be encouraged to learn more about their partners in the other participating countries. Suggested activities to promote cultural exchange can be found on the Web site.

Registration for the Measure Your World event will be open from August 13 — September 14, 2007. Student teams will be notified of their partners by September 21, 2007. The time period for taking the measurements will be September 29 till October 7, 2007.

Measure the circumference of the earth - contest

I got word of an interesting contest where school children will form teams and attempt to measure the circumference of the Earth using the same method as Eratosthenes used back in ancient times.

Any students from USA, Mexico, and Peru can form these teams, whether homeschooled, after-schooled, public schooled or whatever.

Whether you will participate or not, go see the animation that explains the method Eratosthenes used (in the left sidebar).

This sounds like an exciting opportunity to connect geometry, measuring, and math history in a project!

And here's some more information:

---

Please help us get the word out on this new, exciting student centered event!

Measure Your World!

Join us this fall as we pilot a new student-centered project where teams from the United States, Chile, and Mexico partner to replicate the technique introduced by Eratosthenes to determine the circumference of the Earth. Around 240 BC, Eratosthenes used trigonometry and knowledge of the angle of elevation of the Sun at noon in Alexandria and in Syene to calculate the size of the Earth. Windows to the Universe, Educared, and CREA are working together to offer school children in the U.S., Chile, and Mexico the opportunity to form partnerships, take local measurements, and collaborate using the Eratosthenes method to Measure Your World.

All of the information necessary to participate in this pilot student project can be found on the Measure Your World Web sites (www.measureyourworld.org and www.MideTuMundo.org). Student teams must have a parent or adult sponsor to participate. At least one of the team members or adult sponsors must be fluent in both English and Spanish. This event is open to all students in the three participating countries and does not have to be affiliated with a formal K-12 school. Home-schooled children and children participating in after-school programs (e.g. the Scouts, 4-H, etc.) are welcome to participate.

In addition to taking the measurements and calculating the circumference of the Earth, student teams will be encouraged to learn more about their partners in the other participating countries. Suggested activities to promote cultural exchange can be found on the Web site.

Registration for the Measure Your World event will be open from August 13 — September 14, 2007. Student teams will be notified of their partners by September 21, 2007. The time period for taking the measurements will be September 29 till October 7, 2007.

New Math Mammoth books: Clock, Money, and Measuring

Finally the time has come, and I can announce that there are THREE new books for my Math Mammoth Blue Series:

Math Mammoth Clock - about telling time, for grades 1-3. Price: $3.50.

Math Mammoth Money - counting coins, making change, simple money problems. For grades 1-3. Price: $3.

Math Mammoth Measuring - getting familiar with common measuring units for length, weight, and volume. Includes lots of hands-on problems. Mostly for grades 2 and 3. Price: $4.

As usual you can find some sample pages, table of contents, and more info on each book's web page.

The Blue Series and the All Inclusive packages have been updated, accordingly.

New Math Mammoth books: Clock, Money, and Measuring

Finally the time has come, and I can announce that there are THREE new books for my Math Mammoth Blue Series:

Math Mammoth Clock - about telling time, for grades 1-3. Price: $3.50.

Math Mammoth Money - counting coins, making change, simple money problems. For grades 1-3. Price: $3.

Math Mammoth Measuring - getting familiar with common measuring units for length, weight, and volume. Includes lots of hands-on problems. Mostly for grades 2 and 3. Price: $4.

As usual you can find some sample pages, table of contents, and more info on each book's web page.

The Blue Series and the All Inclusive packages have been updated, accordingly.

Math Mammoth Measuring worksheets ready

It seems lately that I'm bogged down by all the work with my books. One of the newest developments was I finally got online and ready two worksheets collection in the new "green" series:

Math Mammoth Measuring Worksheets


Math Mammoth Decimals Worksheets

The books in the green series are worksheets by topic, instead of by grade. The worksheets have been pulled out from the grade 3, 4, 5, and 6 collections (so contain duplicate material with those).

These per topic collections, I feel, will be very helpful for teachers who need worksheets on some particular topic, but with varying difficulty levels.

Check out the freebie sample sheets on the two pages above!

Math Mammoth Measuring worksheets ready

It seems lately that I'm bogged down by all the work with my books. One of the newest developments was I finally got online and ready two worksheets collection in the new "green" series:

Math Mammoth Measuring Worksheets


Math Mammoth Decimals Worksheets

The books in the green series are worksheets by topic, instead of by grade. The worksheets have been pulled out from the grade 3, 4, 5, and 6 collections (so contain duplicate material with those).

These per topic collections, I feel, will be very helpful for teachers who need worksheets on some particular topic, but with varying difficulty levels.

Check out the freebie sample sheets on the two pages above!