This week I began introducing decimals to my class using the resource decimats.
Before we began, we recapped the most important point from last weeks place value - the magic number of 10. I tried to get across that in maths, especially in place value, everything always comes back to the magic number 10. Most of the kids did get this point and it was evident later who did and didn't.
I explained that in the same way, the magic number 10 still exists in decimals. What you exchange it for is just different.
I used these resources a couple times last year (click here), however this week I did it with my whole class instead of a select group, before moving onto groups.
Decimats are a resource which show visually how decimals are smaller than one whole, and visually show that ten tenths fit into one whole, 100 hundredths fit into one whole, and how hundredths are smaller than tenths.
I did find the decimats was useful for the students to quickly understand tenths and hundredths, however progress slowed when I began asking them to add or subtract decimal numbers and they had to exchange hundredths for tenths, or tenths for one whole.
I have also tried to get the kids to explain their mathematical thinking using maths words - like exchange - instead of 'I swapped this for this'. I remind them almost every 30 seconds to call each piece of paper they are talking about by its mathematical name - tenths, hundredths.
Reflection for next weeks learning -
All my students, both those in the target group and those who aren't, need more practice exchanging in decimals. They are getting better at explaining what they have done and why, and using maths language like exchange, but even this still needs some work.
They still need to use the materials to deepen this understanding, I don't feel they are ready for imaging (doing it in their head) just yet.