Class 06 To find the HCF of two given numbers by paper cutting and pasting

CLASS 6MATHEMATICS ACTIVITIES

ACTIVITY 1 – PLAYING WITH NUMBERS

Objective: 

To find the HCF of two given numbers by paper cutting and pasting.

Materials Required: 

Coloured chart paper, geometry box, a pair of scissors, cardboard sheet, glue stick, etc.

Procedure: 

Let us find the HCF of 25 and 40.

STEP 1 : From the red chart paper, cut out a strip of length 40 cm and width 1 cm.

STEP 2: From the black chart paper, cut out a strip of length 25 cm and width 1 cm.

STEP 3 : Paste these two strips on a cardboard sheet and cut out both, the red and black portions from the cardboard.

STEP 4: Now, put the smaller strip (black) below the longer strip (red). Cut out the remaining portion of the red strip as shown below. The length of the cut out is 15 cm.

STEP 5 : Now, put the black strip (25 cm long) and the red strip (15 cm long) one below the other. Cut out the remaining portion of the black strip. Its length is 10 cm.

STEP 6 : Now, put the red strip (15 cm long) and the black strip (10 cm long) one below the other Cut out the remaining portion of the red strip. It measures 5 cm.

STEP 7 : Now, put the black strip (10 cm long) and the red strip (5 cm long) one below the other. On keeping the red strip twice, the length of the black strip is completely covered.

Observations:

Finding the HCF of 25 and 40 means we want to find the greatest length which canmeasure 25 cm and 40 cm exactly.

 STEP 4 shows   25) 40 (1

                  - 25

                   15

i.e., the length of the red cut out is 15 cm.

ACTIVITY 1- PLAYING WITH NUMBERS

3. STEP 5 shows  15) 25 (1 

                     -15

                      10

i.e., the length of the black cut out is 10 cm.

4. STEP 6 shows  10 ) 15 (1

                     - 10

                         5

i.e., the length of the red cut out is 5 cm.

5. STEP 7  shows  5 ) 10 ( 2

                    -10

                       0

i.e., the red cut out measures the black strip twice exactly.

6. Thus, we see that the 5 cm long cut out measures 25 cm and 40 cm exactly. 

Hence, HCF of 25 and 40 is 5.

Conclusion: 

From the above activity, we find that the HCF of 25 and 40 is 5.

Do Yourself: 

Find the HCF of the following numbers by the activity method.

8 and 14 2. 15 and 24  3. 16 and 40

4. 9 and 25 5. 30 and 55 6. 45 and 54