Just to kick it off with a laugh....
Two Tasks
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Note: you might choose to use the file at the bottom of the page which includes arrays with the questions.
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Big ideas
Using derived facts.
10x 5 gives the same answer as 5x10 (commutative property, i.e., changing the order of factors) distributive property, i.e., splitting the factors, 5x12 is the same as 5x10 +5x2. |
Support/PromptsWhat are 10 5's?
What 10x do you know? What 5x do you know? Which is easier? Draw it out (as an array?) What different times tables can you see there? This will come from modelling by the students who can already do it initially. Can also draw it out of the discussions around arrays and pictures of thinking. |
The students at the Early Additive stage are learning to derive their multiplication facts. This means that they can apply a developing range of addition and subtraction strategies to work out unknown multiplication facts from those they already know.
So need to display some facts for kids who don't "know them"...hmmmmm
So need to display some facts for kids who don't "know them"...hmmmmm
Sequenced work
Choose this one because they has changed 12 x 5 into 5 x 12 to make it easier (commutative property) and becuse it is a perfect example of stage 5 using addition to solve the problem. The challenge was getting the kids to unpack that in that bottom line there were 4 12's in the 48 and that there was one more 12 being added to make the five twelves.
During the lesson I decided some predrawn arrays might have been a good ideas so I quickly whipped on up in excel and chucked it into explain everything so when could map the working out on the left onto the array on the right. This would also help when I teach open arrays tomorrow.
Arrays I would have supplied to groups:
Here is a file with the questions and the arrays....
windows_and_arrays.docx | |
File Size: | 84 kb |
File Type: | docx |