Students submit answers to a puzzle which is published weekly on Mondays. School and student performances are recorded and leaderboards are published on the results page. You can sign your school up for free on the ‘About Puzzle of the Week’ page.

http://www.puzzleoftheweek.com/

## Statistics: The Birthday Paradox

This has always been one of those problems that I have loved exploring. I recently found a website that will model the outcome in a brilliantly beautiful way. Here’s a little more about it from the Birthday Problem Wikipedia page:

In probability theory, the birthday problem or birthday paradox concerns the probability that, in a set of

nrandomly chosen people, some pair of them will have the same birthday.

By the pigeonhole principle, the probability reaches 100% when the number of people reaches 367 (since there are only 366 possible birthdays, including February 29). However, 99.9% probability is reached with just 70

people, and 50% probability with 23 people. These conclusions are based on the assumption that each day of the year (excluding February 29) is equally probable for a birthday.

It may seem surprising that the probability is above 50% when there is a pair with the same birthday for a group as small as 23 individuals. This is made more plausible when considering that a comparison will actually be made between every possible pair of people rather than fixing one individual and comparing him or her solely to the rest of the group.

https://en.wikipedia.org/wiki/Birthday_problem

The Pudding’s Russell Goldenberg has created this website to demonstrate this paradox.

Have a visit, have a play and contribute to the data.

I would absolutely use this as a hook the next time I need to tackle statistics with an upper Key Stage 2 class!

**Link**: pudding.cool/2018/04/birthday-paradox/

## Free Download: Mathematical Vocabulary Flashcards

The following ten files are a straightforward set of mathematical vocabulary flashcards. I have grouped them by topic and have written on in small lettering where in the curriculum the term is introduced.

A sample page from the addition and subtraction group is shown below. All of the pages share the same design.

Feel free to share with colleagues – I would love to know how they are being used.

**Addition and subtraction vocabulary 88.96 KB**

**Algebra vocabulary 55.79 KB**

**Data & statistics vocabulary 69.80 KB**

**Fractions, decimals & percentages vocabulary 85.46 KB**

**General & problem solving vocabulary 106.05 KB**

**Geometry (position and direction) vocabulary 98.08 KB**

**Geometry (properties of shape) vocabulary 101.11 KB**

**Measure vocabulary 233.41 KB**

**Multiplication and division vocabulary 83.79 KB**

**Number and place value vocabulary 184.56 KB**