Sunday, December 21, 2014

Dividing decimals with Base 10 Blocks - Hands on Activity

Part of the CCSS is that they want kids to be immersed in concrete ways of doing mathematics.  This is something that I wholeheartedly agree with, even for my higher-level students, because it makes them think about what they're doing.  

Here's a lesson that we did with Base 10 blocks and dividing decimals: 5.NBT.7

This might be something you want to show your kids to model the strategy for them, and then have your students use Base 10 blocks with some other problems.  I used easier problems first and then included problems with remainders.

First, I showed this video:

Next, I split them into partners and had them solve a series of problems.   We did the first one together and then they completed it in partners.  Partner A was the banker first (they traded the hundreds block for 10 tens, a ten stick for 10 ones, etc) to partner B, who was the solver.  Then, they switched roles and solved the same problem.

I grouped the problems into levels of difficulty by A, B, and C.  Here's some examples of them:
A:  3.6 divided by .6
1.2 divided by .2
1.8 divided by .6

B:  7.2 divided by 1.2
6.4 divided by .9
4.2 divided by .7
4.8 divided by 1.2

C:  1.25 divided by .5
3.6 divided by .8 (there's a remainder)
4.8 divided by 1.3 (remainder)

For the early finishers, I challenged them to come up with their own problems for their partner to solve.  I also challenged them to write word problems that related to real-world problem solving (very hard for some students).

I think the hardest part was for them to talk out their thinking (does that make sense?) while doing the mathematics.  Also, they had trouble at first with trading in the Base 10 blocks if they couldn't make any groups.  

A great extension activity would be to have the kids make their own Youtube videos to explain their thinking, which is what we did below.

Overall, GREAT lesson, LOTS of higher level thinking, and it was SO ENGAGING because it was hands-on and challenging for many of the students.