Tag: Wordless Wednesday

  • Fahrenheit to Celsius – Graphically!

    Fahrenheit to Celsius – Graphically!

    Part of Wordless Wednesday

    The beautiful and talented Heather at Freebies4Mom.com sent me a post on An Easy Way to Convert Celsius to Fahrenheit.

    It inspired me to draw the graphs of Celsius in terms of Fahrenheit and Fahrenheit in terms of Celsius.

    The conversion from Celsius to Fahrenheit and back again can be strange. One way to understand it is on a graph. And you can use this to teach some linear algebra too!

    Notice these two intersect at (-40, -40). Which means that -40°F is -40°C!

    Use it to convert temperatures.

    The x values on the red line are Celsius – so find the °C you have and then look at the y-value to convert to °F.

    It’s just the opposite on the purple line.

    Okay, fine. This isn’t the greatest way to convert – but it’s exciting to see it graphically. And it might be easier to convert this way for someone who’s more visual.

    Use it to teach math!

    These two lines are inverses of each other. So the coordinates of one are switched to make the other.

    Also, they mirror image across that 45° line. I marked the line with dashes and wrote $latex y=x$ on it.

    And if you’re into this, their functional composition (both ways) is… x! (not factorial)

    Compare and Contrast…

    Take a look at the way J.D.Roth did it and then look at the graphs I have. Let your students find the way they like the best. And encourage them to create new ways!

    Oh, yeah – and share what happens in the comments!

  • Wordless Wednesday: Fibonacci Baskets

    Wordless Wednesday: Fibonacci Baskets

    I rarely do Wordless Wednesday, but some photos just lend themselves to it!

    These are from IKEA.

    In case you’ve not yet taught the Fibonacci Sequence, it starts with 1, 1 and then each next number is the sum of the previous two numbers:

    • Next is 1 + 1 = 2
    • Then 1 + 2 = 3
    • Then 2 +3 = 5, etc.

    How about some questions…

    • How many sets do I need for the next number? (A set from Ikea has 1, 2, and 3 in it.)
    • How many sets do I need for each number after that?
    • Is there a pattern? Like for the 12th number I need 12-2=10 sets and for the 17th number I need 17-2=15 sets?

    Do you have more questions? Or answers? Share in the comments.

    (150 words later my headline is pretty much wrong, huh?)

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  • Wordless Wednesday: An Example of Count 10 Read 10

    Wordless Wednesday: An Example of Count 10 Read 10

    In an attempt to join the Wordless Wednesday crowd, I’m sharing this photo. But as you can see, for MathFour.com, this is only a Somewhat Wordless Wednesday.

    Before this photo we were discussing size of shirts – a numeracy concept that is visually displayed through the inability for grownups to fit 4T nightshirts on their bodies. Count 10 Read 10 is part of our family’s afterschooling routine.

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