The Scoop on Ice Cream

Classroom Links: biology, technology

Students may enjoy watching a video of the barreleye fish, with commentary by researcher Bruce Robison.

World’s Biggest Boat (page 4)

Classroom Links: biology, mathematics

Snakes, and all reptiles, are often referred to as “cold-blooded”. This is a misnomer. In fact, their blood can be very warm, even hot. It is more correct to say that reptiles are ectothermic. This means their body temperature is derived from factors outside of the body (e.g., ecto=outside) such as the temperature of air or soil. This is in contrast to endotherms (i.e., birds and mammals) that generate their heat internally. 

Activity: Given the above information, discuss the sentence: “Reptiles, including snakes, grow larger in warm temperatures.”  Have students compare two living species of snakes — one in the northern hemisphere and one in the southern hemisphere. Try to choose snakes from the same genus (e.g., Thamnophis is the genus for the garter snake). The genus is always listed first in a scientific name. Or, research the Internet for information on the size of garter snakes in their most northerly part of their range (southern Canada) and the most southerly part of their range (central New Mexico and California).

Have students take the measurements they find to make life size “mock-ups” comparing the length of the snakes. How much larger are the more southerly species?

Backpacking Birds (page 4)

Classroom Links: biology, outdoor education

Dr. Bridget Stutchbury, the lead scientist in this project, is very involved in environmental education. She is keen to get children outside, connecting with the environment through birds. Her lab is working with the faculties of education and environmental science at York University to help schools and teachers use Bird Sleuth, a fun, inquiry-based curriculum for educators.
Click here to visit their website
This program was developed by the Cornell Lab of Ornithology.

Here are Bird Sleuth’s Top 10 Ideas for Birding with Kids.

Devoted Dino Dads (page 5)

Classroom Links: biology, geology

An interview with David Varricchio suitable for young children can be found here.

Mind Games (page 5)

Classroom Links: mathematics

This is a very challenging Mind Game. It may be helpful to have students draw the squares on the chalkboard, beginning at the upper left corner. Keep a running tally and outline each square as it is counted with a different colour of chalk.

KNOW It: Crayons (page 6)

Classroom Links: language arts

Activity: Have students examine their own crayons to look at the names given to them. (You may also wish to bring in several paint chips with their descriptive, and often very colourful, names.) Have a class discussion on how well certain names describe the colours. Have students devise their own crayon colour and give a two or three line description explaining their rationale.

KNOW You: Your Larynx (page 7)

Classroom Links: biology

This video link shows how the larynx works.

KNOW It: Pacific Tree Frogs (page 8)

Classroom Links: biology

As a class or school you may want to participate in Frog Watch, a program in which  local people monitor frogs in their communities. In the US, you can find more information here. In Canada, go to this link.

Both of these sites also have excellent guides for frog identification (with audio).

Keeping frogs in the classroom is a popular activity. There are many ethical issues associated with this practice, however, and, in some places, this is illegal. Before you decide to keep frogs in your classroom, you may want to consider some of the points listed here. If possible, it is almost always better to observe frogs in their native habitat as biologists do. One of the concerns over raising frogs in the classroom is the introduction of non-native species to new habitats. (e.g., raising eggs from elsewhere and then releasing them locally). It is thought that this is one of the ways that bullfrogs have spread throughout North America. These amphibious “thugs” out-compete native species. For more on this problem, go here or here (scroll down to “Threats”).

Theme Section:
The Sweetest Scoop: The Science of Ice Cream (pages 9 – 17)

Classroom Links: chemistry, physics, food science, mathematics

This site from the University of Guelph, gives more background (and some links) on the history of ice cream.

For other interesting ice creams from around the world, go to this site.

For an animated look at how ice cream is made, go to this site.

Activity: Make ice cream in the classroom. Go to KNOW, Issue 1, page 22.

Salt is an important ingredient in making ice cream by hand (above) and in some older styles of ice cream making machines. Salt lowers the freezing temperature of water. The higher the concentration of salt, the lower the freezing point. This site uses diagrams and clear text to explain the physics of this phenomenon.

Activity: Take three clear glasses and half fill them with warm, fresh water. Add one spoonful of salt to one glass and two spoonfuls to a second glass. Stir to dissolve the salt.

Have students take and record the temperature of the water in each glass. Place the glasses in the freezer. After one hour, check the status of the glasses. Are any fully, or partially, frozen? Take and record the temperatures again. Continue to monitor the glasses every 30 minutes or so to see which freezes first, second, and third.

Activity: The availability of ice cream is closely tied to the development of refrigeration.  Investigate other ways in which people preserved food before refrigeration (e.g., smoking, drying, salting). If possible, bring some foods in to the classroom that have been prepared in this way. For example, dried fruit, smoked salmon, or beef jerky. Students could try dehydrating slices  of apple. The fruit is preserved by the removal of all moisture. Have students weigh their apple before and after dehydrating.

Activity: Page 15 lists the daily diet for one dairy cow. Have the students calculate the amount of food and water needed by one cow for one month and one year.

Activity: Have students create an imaginary flavour of ice cream, complete with an ingredients list.