I think the best way to cover the Maths of Practical Life in Third Grade is to divide them up into chunks. Linear Measurement is a good fit with Housebuilding. Baking is a good way to cover Time, Temperature, Weight & Volume. And making items for sale (knitted, crocheted, woven, or felted) during the Fibers & Clothing block is a good fit with Currency.
I've taught Baking (Time, Temperature, Weight & Volume) many times and I definitely have to collect all of my notes and create a new page for the site!
However, in the meantime, I have for you Leah's MLB pages for this block. Bear in mind that I had her do it in sixth grade, so she wrote significantly more than I would expect from a third grader. But I hope they are useful to you nonetheless. Please feel free to write a comment with any questions...
Click on any picture to enlarge it and scroll through the pages with ease.
Leah's absolute favorite part was making candy! She made a VERY detailed main lesson book page about all the stages in candy making (thread stage, soft ball stage, etc.) and carefully drew a candy thermometer. She loved it when we dropped the hot sugar into a cup of cold water and observed how we acted, to see how hot our sugar was without using a thermometer. I have noticed that kids love to imagine a world before time... before temperature... before we had created units of measurement to make life easier! There's a great chapter about baking apple pie in The Evolution of Calpurnia Tate.
In Chapter 18, "Cooking Lessons," Calpurnia expresses her complete and total disbelief, when her mother endeavors to give her cooking lessons for the first time, about how the temperature of an oven is measured (by how long you can hold your hand in before it's so hot you can't stand it).
This (Newbery-winning) book takes place in 1899. So, not that long ago!
Another option is to read the excerpt from The Agony and the Ecstasy: A Biographical Novel of Michelangelo where he describes the elaborate meals his step-mother would cook. Obviously this was from even longer ago. It's an incredible passage... and fascinating to imagine that all of this food was prepared before ovens had thermometers!
I can see from her exit slip questions (the last page of her MLB) what she was still curious about, as well as what concepts she still didn't understand well. For example, I used the biography of Lagrange from the Mathematics are People, Too series, volume 1, to help explain the metric system of a base unit + prefixes. Her question shows me that she believed there was a metric stair before Lagrange and then he helped change it to a new system, instead of understanding that the conference which Lagrange attended was the first to set up the metric system and that it had NOT existed previously.
I totally struggled with trying to figure out what to put in this MLB. (Cooking recipes from simpler to more complex is a no brainer, as is hands-on practice with measuring time, temp, weight & volume. But WHAT do you WRITE?)
And you can see that we really went pretty academic with it. That was because of my uncertainty. When in doubt, my public school side comes out.
The most recent time I did this block was right before Thanksgiving. I actually just had the kids create cookbooks using three ring binders (blue for Math, of course) and we will continue to make recipes all throughout the year and they will compile their favorites into their personal cookbooks.
I think this is the best solution. It encourages you to remember to have cooking & baking as a special all year. It helps them create an artifact. And you can still have introductory pages, as in any cookbook, explaining time, temperature, weight & volume, if you prefer to add that information as well.
Most of your time in a Measurement Unit is in hands-on practice. So relax, cook together, and enjoy it!!!