MATH GRADE 2: Adding Numbers with Zero in any of the Addends with Regrouping

Subject: Mathematics
  |  Educational level: Grade 2

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Adding Numbers with Zero in any of the Addends with Regrouping

 

I. Learning Objectives

Cognitive: Add 2- to 3- digit numbers with zero in any of the addends with regrouping with sums up to 999

Psychomotor: Play or explore manipulative devices

Affective: Show interest and enjoyment in group activities

II. Learning Content:

Skill: Add 2- to 3- digit numbers with zero in any of the addends with regrouping with sums up to 999

Reference: BEC PELC I B3

Materials: stones/seeds/shells, flash cards: Basic addition facts; 2- to 3- digit addition facts with zeros with regrouping, place value compartment

Value: Cheerfulness

III. Learning Experiences

A. Preparatory Activities

1. Drill-Game "How many?"

Prepare pairs of picture cards, each card ranging from 0-9. Example

Example:

 

Call on four pupils to come up front. Flash pairs of cards. The first one to give the correct total makes 1 step forward. Keep on showing pairs of picture cards until one has made 3 steps forward.

Call on another set of pupils and do the same. Continue the game until all pupils have had a turn.

(One-digit number card can also be used alternatively with the picture cards) Be sure that the numbers do not require regrouping.

2. Review

Prepare number cards with 2 and 3 digit numbers.

Put a pocket chart on the board. Have the pupils get their pocket-show-board kit (consisting of a personal pocket chart and small number cards from 0-9). Tell them that they are going to get the sum of the numbers posted on the board. They will show their answers. Post two pairs of numbers and have them show their answers. (The numbers should not require regrouping.) Post from five to ten pairs.

3. Motivation

Act out this problem.

Tessie is helping mother beautify, their house. She picked some flowers from their garden and placed them in vases. She put 16 flowers in their big vase and 10 in their small vase.

B. Developmental Activities

1. Presentation

Ask: What is Tessie doing?

What did she pick? What did she do?

How many flowers were there in all?

Write the number sentence on the board. 16 + 10 = 26

* Discussion and Analysis

What do you think does mother feel with Tessie helping her?

What if Tessie put 34 flowers in the big vase or basket and 26 flowers in the small vase?

What will be the total number of flowers now? Ask for some guesses and list the

numbers given.

Have the pupils represent the numbers with tens and ones.

Show them that since 6 ones and 4 ones are equal to 10 ones. 10 ones can be replaced

with 1 tens.

Emphasize the use of the term regrouping.

How many tens are there now?

What is 26 + 14? Write the equation.

Give other sets of numbers for practice.

Use 2-digit numbers, 3-digit numbers, and combination of the two.

Present: 408 + 129 = ____

 

Show the place value compartments and stones?seeds/shells.

 

Let pupils place the counters (pre-counted and pre-packed) in the place value compartments following the number sentence presented and written on the board.

Ask a pupil to get the 8 ones and the 9 ones.

- How many ones are there in all?

- Should we place all the 17 ones in the ones compartment?

- How many excess ones are there?

Show and explain to them where the stones are to be regrouped and why.

 

H

T

O

4

0

8

1

2

9

 

 

 

 

- How many tens are there in the upper TENS compartment? (Zero)

  • If we put the excess 10 ones in this empty top most TENS compartment, what would be the answer? Add them to the 20 counters in the middle TENS compartment. How many in all? Place them in the lower TENS compartment?

 

- What if the middle Ten compartment was empty, and the 20 counters were in the upper TENS compartment, will the answer change? Why?

(Do the same with the HUNDREDS compartment)

  1. Group Activities

    Activity 1

a. Designate places for the HUNDREDS, TENS and ONES in the classroom.

b. Call on pupils to represent the hundreds, tens and ones in the number sentence discussed using counters.

c. Let the rest of the class read the digits to be added:
8 + 9 =

d. The pupils acting as counters in the 2d addend join the ONES pupils in the 1st addend.

e. The rest of the class says "Regroup" when the union's result is more than 10.

f. These 10 ones go near the TENS place

g. The rest of the class says "0 + 10 = "

h. Only then when the ten ones enters the TENS place.

i. The rest of the class says "4 + 1 = "

j. Pupils assigned as hundred join together in the HUNDREDS place.

- What is 408+129?

- Let us read our human counters.

k. Present other addition numbers.

l. Let other pupils act as counters.

Activity 2

a. Group the class into 3.

b. Each group assigns a leader.

c. Each group has to think of a 3-digit addition combinations with 0 in one of the addends with regrouping.

d. Each group will group the counters they brought (an assignment the day before) according to the addition combinations they made.

e. Each group leader presents the output the way the teacher did.

 

Valuing:

- How did you feel while doing the activities?

- Were you happy? Were you interested in what your group was doing?

 

3. Generalization

What do you mean by "regrouping"?

How do you add numbers with regrouping?

 

C. Application

Let them do the following exercise in their notebook.

1)

107

2)

208

3)

107

4)

187

5)

206

 

+83

 

+25

 

+268

 

+105

 

+ 236

 

 

IV. Evaluation

Find the sum.

 

1)

506

2)

804

3)

909

4)

274

5)

482

 

+345

 

+57

 

+68

 

+107

 

+ 109

 

 

V. Assignment

 

What is their sum?

 

1) 206 + 266 =

2) 85 + 308 =

3) 204 + 518 =

4) 406 + 255 =

5) 405 + 287 =

 

 

6)

25

30

7)

74

20

8)

90

37

9)

80

64

10)

40

39

 

+68

 

+49

 

+15

 

+56

 

+ 61

 

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