A 4-session small group intervention sequence for 1st-grade students focusing on solving addition and subtraction word problems within 20. Students learn to spot color-coded clue words, decide on the operation, and model their work using ten-frames and counters.
Review Addition from Session 1. Remind students that adding joins groups. Today, a new case has arrived: "The Takeaway Game." We start with a big group and some leave. Introduce the orange highlighter.
"Today we investigate subtraction. We are looking for objects that fly away, get eaten, or are lost!"
5-15m
Direct Instruction: The Takeaway Action
Present Clue Word Anchor Chart Page 2 & Slide 6. Show the orange clue words. Model modeling: place 12 counters on the double ten-frame. Cross out or physically take away 4. Count the survivors (8 left).
Teacher Prompt: "When we separate, we start with the whole number. Then we subtract (-) the part we take away."
15-25m
Guided Practice: Slides 7-8
Read Slide 7. Have students spot the clue words "takes away" and "left". On their ten-frames, ask them to make 15 counters. Now, physically remove or flip over 6 counters. Check slide 8 to confirm 15 - 6 = 9.
25-30m
Independent Work Check
Distribute Takeaway Game Worksheet. Direct students to complete Problem 1. Observe if they draw 12 counters in their frames, cross out 4, and write the subtraction sentence: 12 - 4 = 8.
⚠️ Common Misconception:
First graders often get confused about which number goes first in a subtraction equation. Prompt them: "We must start with the whole group—the biggest number before any flew away or were taken."
Intervention Focus: Mixed Addition and Subtraction sorting
30 MINUTE SESSION
Objective:
Students will sort mixed addition and subtraction word problems by selecting the correct operation symbol (+ or -) before solving.
Materials Needed:
Math Mission Task Cards (pre-cut), Keyword Detectives Worksheet (one per student), red and green highlighters, counters.
Step-by-Step Lesson Flow:
0-5m
Keyword Sorting Speed Challenge
Show Slide 9. Point to words on slide (altogether, left, remain, in all) and have students call out "green addition!" or "orange subtraction!" as fast as they can. Cement the association.
5-15m
Guided Practice: Mixed Trials
Display Slide 10. Read the story about Mia's 14 footprints. Ask: "What is the clue word?" (Left). "Is that addition or subtraction?" (Subtraction). Walk students through circling "-" on their worksheet template.
15-27m
The Math Mission Card Hunt
Place Math Mission Task Cards around the table. Students pick a card, read it with a buddy or independently, identify the clue word, and write the math equation on their Keyword Detectives Worksheet in the matching box.
"Read card #1. Is it a green case (+) or orange case (-)? Circle the operation and solve!"
27-30m
Evidence Debrief
Gather group. Check answers for Cards 1 and 2 together. Praise students who successfully sorted different clue actions back-to-back.
⚠️ Common Misconception:
When switching operations, students might get "stuck" on addition and perform addition on a subtraction card simply because they did addition on the previous card. Emphasize searching for the specific action word first.
Math Story Investigators Guide • Page 3/4
TEACHER FACILITATION GUIDE Session 4 / 4
🕵️♂️ Session 4: Story Showdown (Final Assessment)
Intervention Focus: Student-Generated Problem Modeling
30 MINUTE SESSION
Objective:
Students will construct, model, and swap custom addition and subtraction stories within 20 with a peer with 100% independence.
Materials Needed:
Story Showdown Worksheet (one per student), markers, counters, double ten-frame mats, Slides 11-12.
Step-by-Step Lesson Flow:
0-3m
The Master Detective Promotion Announcement
Show Slide 11. Inform students they are at the final level: "Master Story Makers." Today, they will construct their own math mysteries, and their partners must solve them to close the file!
3-15m
Step 1: Drafting the Cases
Distribute the Story Showdown Worksheet. Instruct students to write an addition story in Stage A and a subtraction story in Stage B. Provide options for filling blanks. Model drawing counters on their frames first to check if the numbers work.
15-27m
Step 2: The Peer Showdown Swap
Have students swap papers with a partner. Partners read the custom story, draw the counters in the ten-frames, and write the math equation to solve. Partners sign their teammate's page to confirm "Case Closed!"
27-30m
Mission Accomplished Certification
Present Slide 12. Celebrate the group's success. Review the detective checklist and congratulate them for finishing their intervention successfully!
⚠️ Common Misconception:
First graders writing subtraction stories may accidentally list a larger part taken away than the whole they started with (e.g. "I had 5 files. Clara took away 12."). Ensure they place the largest number first in subtraction.
