Changes

* To analyze how to solve subtraction using standard algorithm.

* To analyze how to solve subtraction using standard algorithm.

* Able to compare the flat long units in solving subtraction.

* Able to compare the flat long units in solving subtraction.

=== '''Materials''' ===

=== '''Materials''' ===

geogebra file: <nowiki>https://www.geogebra.org/classic/uENt3Tj8</nowiki> , <nowiki>https://www.geogebra.org/m/uuk3mjne</nowiki>, black board,

geogebra file: https://www.geogebra.org/m/av6psbf7#material/xt3yPtRg , black board,

 

 

=== '''Subtraction without regrouping''' ===

=== '''Subtraction without regrouping''' ===

28

28

- 15౼        or  this can also be written as 28 – 15 =13 13

- <u>15</u> 

 

<u>'''13'''</u>  or  this can also be written as 28 – 15 =13  

the facilitator writes the sum on the board as written above and tells to solve always from the units. The facilitator asks what is the value of 8-5 the students came up with the answer as 3, again the facilitator asks what is the difference of 2-1 the students came up with the answer as 1. so the difference of the minuend and the subtrahend is 13.

The facilitator writes the sum on the board as written above and tells to solve always from the units. The facilitator asks what is the value of 8-5 the students came up with the answer as 3, again the facilitator asks what is the difference of 2-1 the students came up with the answer as 1. so the difference of the minuend and the subtrahend is 13.

similarly few more sums was explained and given for the practice, this helped the students to get exposure to different methods of solving subtraction sums.

similarly few more sums was explained and given for the practice, this helped the students to get exposure to different methods of solving subtraction sums.

=== '''Subtraction with carry over/ re-grouping:''' ===

=== '''Subtraction with carry over/ re-grouping:''' ===

'''Materials:'''

'''Materials:'''

Black board, geogebra file '''<nowiki>https://www.geogebra.org/classic/ZbnCfzbA</nowiki>; <nowiki>https://www.geogebra.org/m/av6psbf7#material/xt3yPtRg</nowiki>.'''  

Black board, geogebra file https://www.geogebra.org/m/av6psbf7#material/xt3yPtRg '''.'''  

'''Procedure :'''

'''Procedure :'''

From the previous knowledge of the students in subtraction the sums of regrouping was introduced by considering any two number such as 26 and 19.

From the previous knowledge of the students in subtraction the sums of regrouping was introduced by considering any two number such as 26 and 19.

Now the facilitator tell the students to write it in the form of flat long units for the given numbers. Now the facilitator ask, Is it possible to remove 9 units out of 6 units. The students answered “No”. The facilitator asked then how do you solve it? Students thinks. The facilitator explains from the tens place one ten has to be broken into ten units then in the units place there will be totally 16 units which  is shown in the  figure. The facilitator ask Now is it possible to remove 9 from 16? The students answered “yes”. Then what’s  the difference of 16 and 9? the students said 7.yes !!

Now the facilitator tell the students to write it in the form of flat long units for the given numbers. Now the facilitator ask, Is it possible to remove 9 units out of 6 units. The students answered “No”. The facilitator asked then how do you solve it? Students thinks. The facilitator explains from the tens place one ten has to be broken into ten units then in the units place there will be totally 16 units which  is shown in the  figure. The facilitator ask Now is it possible to remove 9 from 16? The students answered “yes”. Then what’s  the difference of 16 and 9? the students said 7.yes !!

In the tens place from 2 tens 1 tens was already broken into ten units therefore only 1 ten is remaining. Now we will find the difference of the tens place value that is 1-1=0. The facilitator tells so the difference of 26-19 is 7. this was also explained by using standard algorithm of subtraction. Few sums were solved with the interaction of the students. And few sums were given to students for the practice.

In the tens place from 2 tens 1 tens was already broken into ten units therefore only 1 ten is remaining. Now we will find the difference of the tens place value that is 1-1=0. The facilitator tells so the difference of 26-19 is 7. this was also explained by using standard algorithm of subtraction. Few sums were solved with the interaction of the students. And few sums were given to students for the practice.