# Activity - Cardinal and Ordinal numbers

## Objectives of the activity

1. Differentiate between the counting number and the total value of the group of objects.

2. Recognize that there could be multiple ways to represent numbers.

3. Identify instances where ordinal numbers are used.

4. Recall and match objects using ordinal numbers.

5. Apply the principles of one-to-one correspondence, cardinality and ordinality while counting.

## Estimated Time

This activity can be conducted in one period. However, the learnings from this session can be extended to deal with concepts such as place value, comparison of numbers and arithmetic operations.

## Materials needed

A bag of assorted objects such as pens, pencils, pebbles, chalk pieces etc. (locally available materials could be used)

## Process

1. This can be done with the whole-class or a group using various of objects.

2. Some of the required objects can be arranged on the table.

3. Students may use visual inspection or touch each object to count each object in a set.

## Developmental Questions/points (Discussion questions/points)

### Part 1

1.Choose an object that doesn’t exist in the room (ex: a television) Ask questions such as ‘how many televisions are there in the room. Students would say ‘zero’.

2. Use the available materials to sequence numbers starting with an empty plate for zero. Ex: The next question could be, ‘How many blackboards are there in the room?’. The answer could be 1. The teacher writes ‘blackboards – 1’ and draws one star next to it. How many ceiling fans are there in the room? Students might say 2, and so on. The teacher again writes ‘ceiling fans – 2’ and draws two stars next to it, and so on.

3. The question could also be altered a little and students could be asked to name an object in the room that is only three in number. They might say ‘the blades of a fan’. One of the students could volunteer to write the number and draw the corresponding number of stars.

4.This activity could be continued for a sequence of numbers.

### Part 2

1. In the second part of this activity, the teacher discusses the use of ordinal numbers and how it differs from ‘regular’ counting with the help of an example. Students could be asked to recall the ordinal positions of the various objects in the previous activity. For ex: What was the ordinal position of pebbles? The answer is fourth. What was the ordinal position of the television? The answer is first .

2. Students could be asked to come up with more instances where ‘first’, ‘second’, ‘third’, etc is used (ex: the standard in which someone studies at school)

## Evaluation

1. Students can be asked to form groups (according to the starting letter of their name, age, number of siblings etc) and determine the number of groups formed, the number of students in each group, and the biggest and smallest groups.
2. Students could be lined up in groups and asked to guess their position on the line.

## Activity Keywords

Cardinal and Ordinal numbers, One-to-one correspondence