Student Challenge Friday

Here is your Friday challenge:

A bag contains only red, yellow and blue lollies. The probability of picking a red lolly is 0.25 and the probability of picking a yellow lolly is 0.40. What is the least number of lollies that could be in the bag?

Extra:

What would be the probability of picking a blue lolly?

Write your answer in the comments with your name and class or ask your teacher to send me a photo of your work :-)

Below are photos of Room 6 working out the problem:

Room 6 found this a really challenging problem.  We decided that if red was 0.25 and yellow was 0.4, then the probability of a blue lolly was 0.35.  From there, we got a bit stuck – most of us turned these decimals into fractions and then didn’t know where to go from there.

With a bit of help from Mr Dawson, we figured out that in a bag of 100 lollies, there would be 25 red, 40 yellow and 35 blue.  We then decided to divide all those numbers by the highest common factor we could find, which was 5.  That reduced the numbers to 5 red, 8 yellow and 7 blue, which means the smallest amount of lollies in a bag was 20.

Missing the Whole

My new groups have been doing a lot of work on fractions in particular part to whole fractions as this is usually where there struggle. 

To start off with we have been looking at basic fractions in a variety of ways i.e. of sets, of shapes, of a number etc while always relating it back to the whole. When we started getting the hang of that we moved onto part to whole where students are given questions involving a part of a fraction and they need to work out the rest of the whole. 

The three level question I used was:

1) Miss Breen has baked chocolate chip cookies for her family.  Her son takes 6 of them when she isn't looking. Her son has taken one quarter (1/4) of the cookies. How many cookies does Miss Breen have left for the rest of the family?

2) Miss Breen has baked chocolate chip cookies for her family.  Her son takes 122 of them when she isn't looking. Her son has taken one sixth (1/6) of the cookies. How many cookies does Miss Breen have left for the rest of the family?

3) Miss Breen has baked chocolate chip cookies for her family.  Her son takes 1052 of them when she isn't looking. Her son has taken one eighth (1/8) of the cookies. How many cookies does Miss Breen have left for the rest of the family?

I wrote this question to consolidate their part to whole fractions work and also to focus on the big idea of 'Distributive Law' (how numbers can be split) to help work out problems more efficiently. These questions were somewhat challenging but I am intending on making them even harder next time.

Here are some pictures of what the students shared back after their problem solving session:

New Groups

Last term I had to say farewell to most of the students that I worked with in term 1 and 2. Now I have 4 new groups of year 4 to 8 students.

Introducing Group 6 & 9:

More group photos to come