## Multiplication & Revising

07 Nov

The grade 5s have wrapped up their first multiplication unit.  The grade 4s are just beginning the journey.  Both began the same way so that is where I will start.

First I posed a multiplication problem to see how much the students understand about the concept of multiplication.  I asked them to model their answers as many ways as possible.

The grade 4s had a choice of two problems and all chose the gummy bear problem:

Here are some of the solutions:

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I was looking for the following concepts, Multiplication is:

Grouping numbers

Area (an array)

Part of Fact Families (with division)

Skip Counting (multiples)

The students presented their work to the class and now we are making multiplication posters showing the five different models for multiplying.  Some completed posters:

Next we will move into multiplying with double digit numbers as well as memorizing our multiplication/division fact families.  I will write another post about memorization strategies.

The grade fives started this way and moved onto different ways to model double and triple digit multiplication problems.  Their project was a mini-book in the math notebooks.

The traditional algorithm is great and works well but it’s difficult for students to understand how it works.  That is why I like to do it in tandem with the area model and break apart models which show the place value while multiplying.  Here is a photo of the area model and a video of the break apart model:

Here is an in depth look at the lattice method.

We still need lots of practice with mental math, not just the times tables, but mentally estimating and multiplying using strategies like rounding and breaking numbers apart.  More to come on this.

Revising

The grade 5s are revising their descriptive paragraph.  Revising is critical for good writing so we talked about using word choice and sentence fluency as we revise.  Can we replace boring words with vibrant words?  Can we combine two sentences into one?  Do most of our sentences start with different words?  Does our writing flow?

Here is the paragraph we revised together.  Today and tomorrow the students are revising their own paragraphs.  I’ve told them I want to see the messiness, all the marking up of their page.  That is how I will know they are learning to revise.  If they erase their work then I can’t tell.   Their final versions will be on their personal blogs so check for them in a few days.