- Subject: Math
- Driving Question: How do we subtract up to 3-digits?
- Pedagogical Method: Inquiry-Based Learning
- Grade Level: 2, 3
- Duration: 90 minutes / 2 sessions
- Delivery Method: Messenger Applications
Students will be able to explore different ways to subtract three digits and then narrows down the fastest method of subtraction.
- Materials: laptops/tablets/Mobile phones
- Subtract up to 3-digit numbers, with and without regrouping.
- Use the vertical alignment to find differences.
- Solve word problems using subtraction.
- Apply subtraction in real life examples.
Keywords: subtraction, minus, subtract, takeaway, difference, columns, regrouping, left, less
- Students should know that subtraction is taking away or making less.
- Students must be able to subtract 1-digit numbers from 2-digit numbers.
Send a simple question first and send the mentimeter link (Link 3) so the students can submit their answers there.
Grade 2: What do you like to eat while you drink your milk?
Grade 3: Which potato chips flavor is your favorite?
After the students submit their answers, give an example (problem of the day), and have students guess how to find the answer and what should be done to solve the problem.
The example can be as follows.
For grade 2:
I love to eat biscuits with my sister while we drink milk. So, I bought 2 boxes of biscuits, and each pack contains 32 biscuits.
My sister ate 47 biscuits. How many biscuits do we still have left?
For grade 3:
I bought 2 boxes of barbecue-flavored pringles. There were 100 chips in each box. My friends came to visit, and we ate some. There were 158 chips left. How many chips did we eat?
When done, have students share the strategies they used to find the answer to the word problem by either sending a picture of their work or sending a voice message explaining their strategy. It is important to highlight that there is no “bad idea” or “bad strategy” - all strategies are correct and can be used. Encourage students to share their questions and wonders by typing them in messages. These messages will be referred to later.
Share that although all strategies are correct and can be used, some are less-time consuming and easier to organize. Share a video in which she/he models aligning the numbers vertically and subtracting.
For grade 2, send Video 1.
For grade 3, send Video 2.
Show the students a poster (Reference 1) which will help visual and auditory learners.
To check for understanding, send Link 2 for students to play and self-assess their understanding.
Have students practice regrouping in subtraction (send Worksheet 1). They are given the option of teaming up with a partner to do the work. Student A will solve the odd exercise numbers, and student B will solve the even ones. When done, they will share and give peer feedback. Those who wish to work independently can do so.
To check for understanding, have students share and give peer feedback. Monitor their conversations in their groups on a messenger application.
Refer back to the messages in which the students typed their questions and reread them. Have students share the answers to the questions they found and welcome new questions that pop up for future investigation.
A poster (Reference 2) that sums up everything will be sent to the students as a summary and a reference.
For homework, send PowerPoint 2 and have students write their response on their copybooks and share a picture of their work with you.
For a final assessment, use Test 1 and the link to the assessment in the file.
For early finishers or advanced students, send Link 3.
For challenged students, send Link 4.