EL Support Lesson
Students will be able to subtract within 20.
Students will be able to explain the steps to subtract with transitional words using a visual number line and partner support.
- Tell students the story problem, "Sandra loves to share! For her birthday she got 20 stickers! She gave six stickers to her friend. How many stickers does Sandra have left?"
- Show students 20 stickers, or draw 20 circles on the board. Tell students that you will subtract to show the stickers that Sandra gave away. Remove six stickers.
- Count chorally as a class to determine that Sandra has 14 stickers left.
- Summarize, "Sandra started with 20 stickers total. She gave away part of the stickers. Sandra kept the other part for herself. We wanted to know how many stickers Sandra kept for herself. Here is a way we can write that: 20 - 6 = 14."
- Point below the equation and read chorally, "Twenty minus six equals fourteen."
- Say, "Repeat after me. Sandra had fourteen stickers left."
Explicit Instruction/Teacher modeling(5 minutes)
- Tell students that today they will practise jumping on a Number lineTo solve SubtractionProblems. Display a number line that includes at least 0 - 20.
- Write 18 - 4On the board, have students read, "Eighteen MinusFour."
- Model finding 18 on the number line, and have students repeat, "Eighteen" exaggerating the NSo that 18 is not confused with 80.
- Ask students whether the numbers will get bigger or smaller when you subtract. Ask students to point in the direct that you will move on the number line to subtract.
- Think aloud, "Yes, when I add the numbers get bigger and I move ForwardOn the number line." Tell students to point in front of themselves and repeat, "forward."
- Say, "With subtraction I will start will the whole, and subtract one part. I will need to move BackwardOn the number line to find the missing part." Have students point behind themselves and repeat, "backward."
- Refer back to the problem and say, "I need to subtract four." Model jumping back four times on the number line counting each jump, "One, two, three four."
- Ask students which number you landed on (fourteen!). Solve the equation and have students read the equation with you as you point below, "Eighteen minus four EqualsFourteen."
Guided practise(10 minutes)
- Distribute the Froggy Subtraction number line and game piece to each student. Tell students that they will follow along on their number lines to solve subtraction problems, and then play a game with a partner.
- Write 15 - 3On the board and chorally read, "Fifteen minus three."
- Direct students to line the frog up with 15, as you model on the number line.
- Ask students whether you will move forward or backward on the number line to subtract three. Think aloud, "As I subtract, the numbers get smaller."
- Model jumping back three numbers as students follow along with their number lines. Remind students to count the "jumps".
- Finish the equation 15 - 3 = 12, and have students read with your chorally.
- Continue with a few more examples using the number line to subtract.
Group work time(10 minutes)
- Distribute a die to each partnership, and tell students that they will now play Froggy Subtraction with their partner.
- Project the instructionsm and explain the steps to play the game. Each player will start at 20. Player A will roll the die, and count that many jumps backwards. Player A will say a number sentence, "____Minus ____Equals ____."
- Player B will roll the die, move the frog that many jumps, and say a number sentence.
- The player must land exactly on 0 to win. For example, a roll of four cannot win if the player is on 3.
- The first player to reach the fly wins! (Optional- tell students to add to return to the lily pad to win.)
Additional EL adaptations
- Display a poster with numerals and number names 0-20 for reference.
- If students do not know number names in English, allow them to say the number names in their home language (L1).
- Play Froggy Subtraction in a teacher-led small group.
- Challenge students to explain the steps to subtract using a number line in their own words.
- Remind students that the number line is a tool to help make subtraction easier. Ask students to describe other strategies for solving subtraction problems.
- Circulate as students play the game to check for understanding. Observe that students are counting the jumps on the number line, and not including the initial number in the count.
- Listen for students to say a number sentence after each turn.
- Prompt students to describe the steps to subtract using a number line in their own words.
Review and closing(5 minutes)
- Call the class back together and ask them whether they enjoyed the game. Show students how to give you a thumbs up if they enjoyed it, sideways if it was OK and down if they did not like it.
- Allow students an opportunity to share their opinion with a partner using the sentence frame, "I did/ did not like the game because ____."
- Move the game to a centre to allow students further practise using the number line to subtract with a small group.