• 12-15

The students: 6 graders, 12 years old

Math lesson (45 min.)

Lesson aim: To explore even and odd numbers

Materials: cards with numbers

At the beginning of math lesson each student notice cards with numbers. They started ask: "What we are going to do?"

Therefore, I explained the task: "Your task is to sort numbers in groups".

Numbers were: 124; 12, 33, 48, 69, 55, 41, 66, 16, 200, 15, 72, 8.

The beginning of the lesson was very interesting because they started ask questions: "How many groups to make?"

"How can I divide into groups if I don't know what to do?"

Despite the fact that they were confused, they suggested lots of different groups.

I want to share with you:

-Very predictable group - the group of 1-digit, 2-digit and 3-digit numbers

-Less predictable group - numbers from 1 to 100 and  from 101 to 201

-Unpredictable group - add each number digits till you will get one digit number, then divide into group numbers till 5 and bigger than 5.

Each time after someone had a new group we shared grouping idea with class on the board.

Limitation - it was not allowed to use the same idea for grouping.

To reach my aim faster, they had to sort numbers just into two groups.

After a few try we reached the aim. They found a group of numbers divisible by two and impossible to divide by two without remainder.

Together we came to conclusion about even and odd numbers. Now students are able to explain which numbers are odd and which are even.

They found  that to tell whether a number is even or odd, look at the number in the ones place.

An even number ends in 0, 2, 4, 6, or 8.

An odd number ends in 1, 3, 5, 7, or 9.

Next lesson we are going to work just with side of group - divisible by two (124, 12, 48, 66, 16, 200, 72, 8)

P.S. Homework task: To find all possible signs (parameters) of numbers helpfull to know in numbers grouping task.