MATHletes Weekly Challenge
MATHLETES WEEKLY CHALLENGE
What are Weekly Challenges?
Weekly Challenges are specifically selected additional training problems & exercises assigned by the MATHletes Challenge coaches. Weekly Challenge training problems do not give students extra MATHletes Mastery points and do not have a direct impact on leaderboard standings  they are used as a 'tiebreaker' in the case of ties in playoff qualification. The main part of the Challenge is working independently in Khan Academy: all of students' work in their KA accounts will give them points for the leaderboards, including (but not only) the weekly focus exercises.
WHEN & HOW OF COMPLETING THE WEEKLY CHALLENGE
Weekly Challenges for the Student Challenge and Schools Challenge will be posted here every Wednesday at 12noon. You will have one week to complete the Challenge for your class/year.
Teachers: You may assign the exercises & training problem for students to complete individually, or you may work on the problems together as a class and submit one answer. We leave this to each teacher to decide what is most motivating in your classroom.
DO WEEKLY CHALLENGES COUNT FOR LEADERBOARD POINTS?
Students' leaderboard standings are based ONLY their work mastering skills in Khan Academy. Weekly Challenges provide extra motivation, recognition, and tests of MATHletes' determination as the competition progresses. For student challenge competitors, these problems will help prepare MATHletes for the playoffs and will help the MATHletes coaches if there are tiebreakers for provincial qualification.
Schools and Students who correctly answer the Weekly Challenge will be posted in the "Weekly Challenge Winners Circle" check back every Wednesday to see if your answer was correct for the previous week!
Two types of Weekly Training Challenges:
 TRAINING PROBLEM for each class level will be posted on at mathletes.ie. You will submit your answer for your class level problem, along with your Khan Academy Username. As the competition progresses, these problems will become more difficult.
 FOCUS EXERCISESare specific exercises that you should focus on in your Khan Academy learning dashboard. They are specially selected to help you complete the Training Problem for the week. To complete these exercises:
Student Challengers: Login to your Khan Academy account and click on the link to the focus exercise below for your class/year  this should take you straight to working on the exercise in your KA account. If that doesn't work, you can search for the exercise name in the top search bar in your learning dashboard.
Teachers: You should assign these focus exercises to your students as part of the Schools Challenge. Watch this video explaining how to assign focus exercises by making a recommendation to your whole class:
Weekly Challenge #10: March 11^{th}
Focus exercises
Class/Year

Exercises in Khan Academy
(click link when logged into Khan Academy to complete) 

4th class (ROI)/ Primary 6 (NI) 
(1) Solving basic multiplication and division equations (2) Area Problems 
5th class (ROI)/ Primary 7 (NI) 
(1) Writing and interpreting decimals (2) Graphing Points 
6th class (ROI)/ Year 8 (NI) 
(1) Negative numbers on the numberline without reference to zero (2) Positive and zero exponents 
1st year (ROI)/ Year 9 (NI) 
(1) Experimental Probability (2) Comparing Probabilities 
2nd year (ROI)/ Year 10 (NI) 
(1) Sample spaces for compound events (2) Experimental Probability 
3rd year (ROI)/ Year 11 (NI) 
(1) Area of triangles 2 (2) Area of parallelograms 
4th year/TY (ROI)/ Year 12 (NI) 
(1) Graphing systems of inequalities (2) Solving similar triangles 1 
5th year (ROI)/ Year 13 (NI) 
(1) Area of quadrilaterals and polygons (2) Compass constructions 2 
Training Problem set
4^{th} class (ROI)/Primary 6(NI)
A euro coin was changed into 16 coins consisting of just 10 cent coins and 5 cent coins. What is the product of the number of each type of coin in the change?
5^{th} class (ROI)/Primary 7(NI)
Mrs. Bakesalot made a batch of biscuits for Patrick, Christopher, Amy, and Mary. The kids shared the biscuits equally and finished them all right away.
Then Mrs. Bakesalot made another batch, twice as big as the first. When she took the cookies off the cookie sheet, 6 of them crumbled, so she didn't serve them to the kids. She gave the children the rest of the cookies.
Mr. Bakesalot came home and ate 2 cookies from the children's tray. Each of the children ate 3 more cookies along with a glass of milk. Full, they decided to save the last 4 cookies.
How many cookies were in the first batch?
6^{th} class (ROI)/Year 8(NI)
The floor of a square hall is tiled with square tiles. Along the two diagonals there are 125 tiles altogether.
How many tiles are on the floor?
1^{st} year (ROI)/Year 9(NI)
A Roman dice in the British Museum has 6 square faces and 8 triangular faces. It is twice as likely to land on any given square face as any given triangular face. What is the probability that the face it lands on is triangular, when thrown? Express you answer as a percentage.
2^{nd} year(ROI)/Year 10(NI)
A 3 x 3 square grid is subdivided into 9 unit squares. Each unit square is painted either white or black with each colour being equally likely of being chosen randomly and independently. The square is then rotated 90 degrees clockwise about its centre, and every white square in a position formerly occupied by a black square is painted black. The colours of all other squares are left unchanged. What is the probability the grid is now entirely black? Give your answer in fraction form
3^{rd} year(ROI)/Year 11(NI)
is a parallelogram (where the vertices are labelled in clockwise order ). Suppose that and . What is the area of the parallelogram?
4^{th} year TY(ROI)/Year 12(NI)
In the computation below, each letter represents one distinct digit. What digit is represented by U?
5^{th} year(ROI)/Year 13(NI)
Claire is using a maths program on her computer to inscribe a regular polygon in the unit circle. Find the minimum number of sides that Claire's regular polygon can have if the difference between the area of the circle and the area of the polygon must be less than .
The weekly challenges are now finished for the 2015 MATHletes Challenge. Check out the Past Challenges and Solutions and the Winners Circle.