LESSON PLANNING OF SUBTRACTION OF 3-DIGIT NUMBER (WITHOUT BORROW)

Subject Mathematics

Grade 2^{nd}

Students` Learning Outcomes

- Subtract ones from 3-digit numbers without borrow.
- Subtract 2-digit numbers from 3-digit numbers without borrow.

Information for Teachers

- Subtract is one of the four basic arithmetic operations;

- It is the inverse of addition.

- General equation of subtraction is c – b = a
- If nothing is left at any place write zero there, but not omit the place.

- While teaching the lesson, the teacher should also consult with textbook at all the steps where and when applicable.

Material / Resources

Writing board, chalk / marker, duster, number tray, counting frame, pebbles, beads, paper strips

Introduction

- Place flashcards with 2-digit numbers on the table.

- Ask students turn by turn to pick any two cards.
- Decide which card has bigger number.
- Subtract smaller number from bigger number by solving on board.

Development

Activity 1

- Give number tray made up of empty match boxes along with some pebbles, in groups.

- Write a three digit number on writing board as such 346 and ask students to represent number by putting pebbles in appropriate part of tray.

- Now write a 2-digit number as such 23 and ask students to takeaway this amount from material they presented on number tray. Ask the answer from the groups on the basis of material left in the number tray. (323)
- Now replace 1-digit number with 2-digit number (without borrowing) as such 4. Ask again to take away 4 pebbles from unit part and describe answer (pebbles left at different places).
- Repeat this activity for other numbers.

Activity 2

- Give counting frame along with some beads in group.
- Write a 3-digit number on writing board (minuend) and ask students to represent number by inserting beads in appropriate column strings.
- Write a 1-digit number (subtrahend) and ask students to take away from the given number using counting frame. Count the number of beads left in unit, ten and hundred string, and tell the number, this is the answer of subtraction question.
- Replace 1-digit number (subtrahend) with 2-digit number (without borrowing).
- Ask again to take away some beads from units and tens part and describe answer (beads left in different strings)
- Then replace 2-digit numbers (subtrahend) with 3-digit number (without borrowing), ask students to take away beads from unit, ten and hundred accordingly and describe answer by counting remaining beads in each string.
- Repeat this activity for other numbers.

Activity 3

- Give paper strips to students containing questions of subtraction (1 and 2 –digit from 3-digit without borrowing).
- Ask students to take any three strips at random and solve the drawn questions.
- Interchange strips with fellows for peer assessment.
- Call few students to solve their question on board.

Sum up / Conclusion

- Subtraction is simpler when taking away a smaller number from bigger number.
- Write the values in column under headings units, Tens & Hundred.
- Subtract units from units, tens from tens and hundreds from hundreds.
- If nothing is left at any place write zero there, but don’t omit the place.

Assessment

- Write some subtraction questions on writing board (2 or 3 digit from 3-digit without borrowing) such as; 456 – 23 and ask students to solve the question in their notebooks.

Follow up

- Teacher will assign few subtraction questions to solve (3-digit from 3-digit without borrowing) as home work.
- Ask students to write and solve at least 5 questions of subtraction (3-digit from 3-digit numbers)
- Ask the students to solve the questions given in their textbooks.