1. Teacher secretly writes a number or draws a shape on a blank playing card

2. Child A wears the hat. The teacher attaches the card to the front of the hat so that it can be viewed by the rest of the group but is unknown to child A

3. Child A must ask questions, that require a Yes or No answer only of the rest of the group, in order to find out what is on the card on their hat

The role of the teacher is to keep the game moving, so that the involvement of the children is maximised

Children may need to be given some guide as to the range of numbers that the card could be within. E.g. Your card is a number between 1 and 50

Children may find using a "100 square" helps them to identify the number on their card, as they find difficulty in visualising the series of numbers. Use of a number grid or 100 square is also an excellent support for the development of children’s understanding of the elimination process as they physically have to remove/cross out unwanted numbers. "Good questions" can therefore be identified as ones that enable them to remove "lots" of numbers. An additional advantage of children having a "100 square" in front of them when playing the game is that they see the patterns in the numbers either remaining or being removed

The use of smaller grids i.e. numbers up to 10 or 20 may be more appropriate with younger children. Alternatively, using a number line for modeling and visualising was found to be effective

Teachers can interject to help children identify good strategies when eliminating e.g. choosing a number half way in the range to go with the question "is it bigger than …."

The game can cover all types of numbers so that "big numbers" can be used when appropriate e.g. millions

If children are not allowed to repeat any term/expression in subsequent questions this makes the children think of alternative ways of expressing themselves mathematically e.g. "is it bigger than 20", "is it greater than 30". It also encourages the children to think of an alternative type of question

Teachers need to help the children refine their questions so that they are more effective questions.

Keeping a tally of the number of questions needed to identify the card not only gives children practice of tallying but can also encourage children to set themselves targets

Cards can be reused provided they are made of a durable material.

Writing the child’s name on the back of the card enables the teacher to, avoid any undesirable repetitive use of a card, make formative assessments and plan for a child’s progression

Keeping a record of the children’s questions, as they say them, on a large sheet of paper can form a "prompt" if conveniently displayed in the classroom for children who need to develop their confidence and questioning skills

Children often incorrectly use the word "side" in the 3D context e.g. when referring to a cube say it has 6 sides. This is an ideal opportunity for the teacher to reinforce the correct meaning of terms and differentiate between "side" in a 2D context and "face" in the 3D context

The game encourages the development of children’s ability to visualise mathematical shapes and numbers

The game encourages the children to hold information in their heads

The game carries a Health Warning – Head Lice do travel on shared hats

List the language you would expect from the year group/class that are undertaking this activity. The list should be seen as evidence of progression within the Scheme of Work and can be used as part of the monitoring process. Guidance can be obtained from the Mathematical Vocabulary Book – National Numeracy Project (for details see Resources Section of this booklet)

is it a number

is it even

is it odd

is it bigger than

is it larger than

is it smaller than

is it less than

is it a multiple of

is ...... a factor of it

is it prime

is it a perfect number

is the sum of its digits even

is it a 3 digit number

is it in the millions

is it a whole number

is it between .......... and ..........

is it a number on the 12 hour clock

is it a number on the 24 hour clock

 

is it 2D

is it 3D

is it 2 dimensional

is it 3 dimensional

does it have an even number of sides

does it have an even number of edges

are all the sides the same length

are all the edges the same length

are all faces the same shape

does it have line symmetry

does it have rotational symmetry

do the faces meet at a point/vertex

are there any right angles

does it tessellate

is it a prism

are any faces curved

is it a regular shape

if I fold it in half does it match