f65 Mental Mathematics - An AskERIC Lesson Plan
Lesson Plan #:AELP-ATH0014

## Mental Mathematics

### May 14, 1997

#### Description:

The purpose of this lesson is to teach students how to work mentally with numbers, as to nurture number sense, and create a foundation and enthusiasm for mathematics. This is a fun and interactive way for students to learn, and helps to create a fee ffb ling of accomplishment.

#### Goal:

Students will understand some ways in which to compute mathematics problems mentally.

#### Objectives:

The students will be able to:

1. mentally figure out the answers to problems without the use of paper, pencils or calculators

2. explain how they came up with the answer given

#### Background Information:

This activity can be used with students of all ages, however, I feel that students at the fourth-fifith grade levels could handle the concept of mental mathematics more readily. The lesson teaches them ways in which to work out math problems in their heads, without the use of any materials.

#### Concepts:

The students will be able to:

1. think before they start computing

2. utilize their minds instead of manipulating tools

#### Materials:

Chalkboard and chalk

#### Procedure:

1. Open the lesson with the following statement: "Students, today we are going to do some mental math, so put away your pencils and get ready to have some fun!"

2. Ask the question: "Does anyone know what mental mathematics is?" Hold a discussion and accept all answers.

3. The teacher will then use four activities to introduce the concept of mental math, which are: Give Me a Date, Raise me a number, Multiplication shortcut, and numbered square.

4. Give me a date is simply asking the students to come up with as many operations possible for a given date. The teacher will ask the students to give him/her any date that they would like, and will write it on the board. Underneath each number, the teacher will place a box to record the operations the students generate as a class.

5. Raise me a number will begin by the teacher handing out basic playing cards to a group of two students. The cards will include the King, Ace, 1,2,3,4,5,6,7,8, and 9. The teacher will ask several math questions as the students take holding up the cards that show the answers to the problems given. (King=0, Ace=1)

6. Multiplication shortcut is an activity to encourage the use of shortcuts while figuring out math problems mentally. The teacher will select a student to come to the board. The student will wait until the teacher gives the problem to write on the board, and then has 30 second to answer the problem.

The questions will start out easy, using the strategy given before the activity. The problems will only involve numbers ending in five.

Here is an example:

25*25=625.

All answers when ending in fives will automatically end in the number 25.

The trick is to add one to the first number, and then multiply the two numbers together, adding them to 25. 25*25=2+1*3=6 added to 25=625. 7.

Numbered square is simply drawing a square and writing six numbers on the board. The numbers should be placed on, in, around, and under the square, so that the students will have to explain the numbers asked for.

Example: The teacher say, "In and Above", the students response would be to find the numbers that are in the square and above it, and then add, subtract or multiply them (which ever operation is specified before the question is asked). The student would be expected to say the problem correctly.

Example:"5 plus 9 equals 14".

#### Assessment:

1. The teacher will be listening to the students responses and monitoring facial expressions and questions carefully, jotting down notes for each student.

2. The teacher will ask the students the following questions:

A. why do you think that it is important to learn how to do math mentally?

B. how do we use mental math in our everyday lives?

C. ask for student suggestions on other ways in which we could compute math mentally.

D. ask if they followed the instructions, and if they understood the concept behind 25 the activities. 0