After our quick images, we moved into pre-shaded grids for students to look at equivalencies of decimals shaded on tenths and hundredths grids. We flew through until we hit the tenths grid with 5 1/2 tenths shaded and hundredths grid with 55 hundredths shaded. The students could see they were equivalent by the pictures, but many had a tough time explaining why. When someone did say “A half of a tenth is 5/100” another student said, “But I thought a half of a tenth was 1/20?” What a cool conversation! They left class yesterday with this question still lingering so I had them just jot what their group had talked about in relation to these pictures…
At this point students were starting to have trouble thinking about writing a decimal that was a half of the place value to the right, so they stayed in fractions where they comfortably can represent half a fractional piece.
We started our conversation with this today and broke up the grids to prove that 5/100 is equivalent to 1/20 and equal to 1/2 / 10. Students were comfortable with the half of a tenth represented in the hundredths, however they made it perfectly clear that they much preferred the hundredths grid because it was much easier to read:) So, of course, then I pushed them into the thousandths grid. We started with 1/4 shaded on a hundredths grid and 1/4 on a thousandths grid. They comfortably wrote 25/100=250/1000=25%-.25=.250. Then we went to a hundredths and thousandths grids with 1/8 shaded. Great convo that we will have to build on tomorrow, but as always, I need more math time!! I had them leave on a reflection prompt about what noticings they had during our work today. For the students who could easily see these equivalencies, I told them to write me some wonderings they may have. I got quite a range of great things. The predominant question was about the fraction/decimal in a decimal. I struggle with how to address this because it visually is not as appealing to me as the fraction/decimal within a fraction. I am comfortable writing 1 1/2 /4 = 3/8 but to write the fraction in the decimal does not work. I never really thought about it much before, but how funny that we can write a fraction of a fractional piece and it is readable, but to try with decimals, not so much. The only way I see to address this is to do many more grid shadings to get comfortable with these equivalencies, but I do so appreciate their curiosity about it!
And I especially love these last two because it gives me the feeling that I have created a safe place for my students to put confusion out there. I LOVE LOVE LOVE this ❤