Tuesday, April 12, 2016

Maths session with Dinah: Fractions


Where do we start? What do we know about fractions? Here is a rich task to get us started and find out what you know. 

Leave 5 minutes for students to struggle and make a start. Come back together. Start with the group who has a blank page. Ask them to share what they were thinking? What were you discussing?

Students responded with the questions they were asking each other. E.g. What is 1/5 of 200?  

Teacher responds with a comment about that this is exactly the type of question you need to be writing down.  Teacher now asks: do you know what you need to do next.

Teacher moves to the next group with the least on the page. She uses the first group and asks them to explain to the new group what their next step is.

As the teacher moves around she uses the k owl edge and next steps of the group to build on and connect to new learning.

Don't be afraid to move to the side to fill a gap. How do we make sure our fractions are equal sizes?  What happens when the denominator is an even number? What happens when the denominator is odd? 

Comes to the last group who has the answers written down. The thing that is missing here is I don't know how you got these numbers and I don't know if they are the right numbers. Explain to us, where did you start?  

1/10 of 200 = 20 because 1/10 of 100  = 10. 10 x 2 = 20. 

Now pull out the equipment and demonstrate how to work out the rest of the numbers.  Make sure you use correct language.

Reorganise these so that they are eAsier to work with:

What fraction does the peanuts and the raisins make? 2/4 or 1/2.  How many half weigh? 100!  

These 5 things = 100g. How many tenths fit into fifths? 2. So how many grams is 1/5 of 200? 40.

Demonstrate how to solve part of the problem using the linear model. 

Now I want you to use the model to work out how many grams of peanuts.  Use the model and use the division. 

(H)
E = experience
l = language 
P = picture
S = symbol 

Now try this! Independent activity idea:
Once again, teacher uses each group to explain just on step or phase of how you solve the problem using the model.

Now try this! 

Tri-squares:
Draw half a dozen Tri-squares...
Split into 3. If the whole is 12, how many is each part worth?

Split into 6 equal parts. Now how many is each part? 

Split into 3 equal parts. How much is each worth if the whole is 1/2?

Now split into 3 unequal parts. If the whole is 12, what is the value of each part? 


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