Well...maybe that should have said 37 degrees since we use the Celsius scale! Today was the perfect day to talk about certain 'benchmark' temperatures on the thermometer. This morning, we began by recording the current temperature (-5 degrees Celsius) on the thermometer. We talked about what we saw outside (ice and snow), and what we had to wear that morning (hat, boots, mitts). Next, I gave them the standard body temperature of 37 degrees Celsius. From there, I would suggest ideas and they would problem solve to see how close they could get to guessing the degrees Celsius. We learned that water freezes at 0 degrees, and boils at 100 degrees. We also found out that the average refrigerator temperature is 7 degrees, and that an indoor recess is usually announced at -25 degrees. We had a lot of fun guessing the new temperature on the thermometer each time we came in from recess, and found out that we had a 15 degree temperature rise over the course of the day. The students were so interested in this topic that they asked me to find hottest/coldest record temperatures for Ottawa, Canada, and the world! For the record, the hottest recorded temperature on earth was 57.8 degrees in Libya back in 1922. The coldest was -89 in Antarctica in July of '83. See our labelled thermometer below:
For the past couple of weeks we have been learning strategies to strengthen our ability to add numbers in our head (mental math). Here's an experiment for you to try! Calculate 5 997 + 3 243 (Don't read any further until you have an answer!). Did you grab a pencil and paper? As adults, many of us were taught how to add numbers by writing them in columns, and then adding and 'carrying' across the columns. Usually, we were taught this was the only way to solve questions like this. But is this the quickest, and easiest, way to add numbers? The students have been learning how 'friendly numbers' can actually allow them to perform addition problems like this in their heads (and with greater accuracy than the traditional algorithm). Looking back at the question above, notice how we could easily make the 5 997 more 'friendly' by adding 3 and creating 6 000? Notice how we also could have simply taken that extra 3 from 3 243 to make it the friendlier 3 240? Now all we would have to do is add 6 000 and 3 240, for a total of 9 240. Much easier (and quicker) than all that carrying involved with the algorithm. On Monday, students were shown the algorithm approach, and were asked how it was the same/different from the strategies we were using. It was interesting to hear the conversations, and it was clear that they understood exactly why the algorithm 'carries' numbers over to other columns. Flexibility in his/her math thinking is one of the greatest skills your child can have. Mental math is one way for your child to demonstrate this!
Here are some photos of our Math Wall charts explaining our discoveries: |
AuthorRoom 139 is the home of: Archives
May 2012
Categories |