The rugby world cup math challenge
It's a little known fact that there's a major sporting event on in Japan called The Rugby World Cup and the USA is out there with a team:
What is Rugby? Great question. To keep it short, think football - but throwing the ball backward not forward. Like football, it's also a very tough game but the players wear no protection. Big and little kids alike are really excited about the Rugby World Cup. Here at Komodo we’ll be tuned into the action and supporting the USA all the way to the final!
To get into spirit, we’ve made a rugby math challenge for all the family. There are 10 rugby math questions, arranged in ascending difficulty - from 5 year old finger-counters to a few head scratchers for teenagers and grown ups.
The one minute video above explains how the scoring works, but here’s a summary:
Try = 5 Points
Conversion Kick = 2 Points - but remember you only get to take conversion kick after a Try!
Penalty Kick or Drop Goal = 3 Points
1) How many points would you get for scoring a converted try (try + conversion) and a penalty kick?
2) How many points would you get for scoring an try, and three penalty kicks?
3) How many points would you get for scoring four drop goals?
4) In a famous match in the 2011 World Cup, South Africa scored two converted tries (try + conversion) and a penalty kick, while Wales scored a converted try and three penalties. What was the final score?
5) What's the smallest score a team can make more than one way? (count penalties and drop goals as the same thing!)
6) What's the highest number of points you can't score in a rugby match? (Hint: list the scores you can make!)
7) Let's say Tonga beat New Zealand 15 - 0 in the final. How many different ways can this score be made? (count penalties and drop goals as the same thing!)
8) What is the lowest score draw, where one team scores no tries but the other team scores at least one try?
9) In a 2011 world cup match, England beat Scotland 16-12. How many different ways can you find for each team to score that many points? (count penalties and drop goals as the same thing!)
10) Poor Japan. In the 1995 world cup New Zealand beat them in a match by 145 points to 17 - a tournament record for the number of points. New Zealand didn't score any penalties or drop goals. What's the greatest number of tries they could have scored? What's the smallest?
Scroll down for the answers!
I’m Ged, Co-founder of Komodo, ex-math teacher and dad. If you have any questions please get in touch.
About Komodo – Komodo is a fun and effective way to boost K-5 math skills. Designed for 4 to 11 year olds to use in the home, Komodo uses a little and often approach to learning math (20 minutes, three to five times per week) that fits into the busy routine. Komodo users develop fluency and confidence in math – without keeping them at the screen for long.
And now we've got Komodo English too - check it out here.
The Answers
1) How many points would you get for scoring a converted try (try + conversion) and a penalty kick?
Try = 5, conversion = 2, penalty kick = 3 Total = 10
2) How many points would you get for scoring an try, and three penalty kicks?
Try = 5, penalty kick = 3, penalty kick = 3, penalty kick = 3 Total = 14
3) How many points would you get for scoring four drop goals?
Drop goal = 3, 4 x 3 = 12 points
4) In a famous match in the 2011 World Cup, South Africa scored two converted tries (try + conversion) and a penalty kick, while Wales scored a converted try and three penalties. What was the final score?
South Africa 17 Wales 16
5) What's the smallest score a team can make more than one way? (count penalties and drop goals as the same thing!)
The answer is 10. It can be made as two unconverted tries ( 5 + 5 ) , or a converted try and a penalty/drop goal (7 + 3).
6) What's the highest number of points you can't score in a rugby match? (Hint: list the scores you can make!)
You can make 5 (an unconverted try), and then 8, 11, 14, etc by scoring goals; you can make 6 (two goals), and then 9, 12, 15, etc. by scoring further goals; you can make 7 (a converted try) and then 10, 13, 16, etc. by scoring goals. Therefore, you can make any score above 5, and 4 is the largest impossible score.
7) Let's say Tonga beat New Zealand 15 - 0 in the final. How many different ways can this score be made? (count penalties and drop goals as the same thing!)
There are three ways to score 15: a) 3 x tries ( unconverted ) b) 5 x penalties c) try, try + conversion, penalty
8) What is the lowest score draw, where one team scores no tries but the other team scores at least one try?
If one team scores not tries then the score will be a multiple of 3: 6,9,12,15 Of these scores you cannot make 6 or 9 when you score a try ( with conversion or not ). However you can make 12 from a try (5) and a converted try (7). The answer is 12 - 12.
9) In a 2011 world cup match, England beat Scotland 16-12. How many different ways can you find for each team to score that many points? (count penalties and drop goals as the same thing!)
16 can be scored as: a converted try(7) and three goals (3x3); or two unconverted tries(2 x 5) and two goals (2 x 3). 12 can be scored as: four goals (4 x 3); or a converted try (7) and an unconverted try(5)
10) Poor Japan. In the 1995 world cup New Zealand beat them in a match by 145 points to 17 - a tournament record for the number of points. New Zealand didn't score any penalties or drop goals. What's the greatest number of tries they could have scored? What's the smallest?
If New Zealand didn't convert any of their tries, they would need 145 ÷ 5 = 29 tries. That's the highest number of tries they could have scored. They didn't convert all of their tries, because 7 doesn't divide evenly into 145, but if they missed just one conversion, they would have scored 5 + 140, which is an unconverted try and 20 converted tries, a total of 21 tries. In fact, that's exactly what they did.
