Kindergarten Spring Math — Compose/Decompose to 10, Addition & Subtraction within 10, Teen Numbers as Ten-and-Ones, Measurement, and Classification
Lesson 7 30 min math.gK.s.lesson_07

Meeting the Minus Sign — Subtraction as Take-Away

Skills targeted
Objectives
  • Students can read and write the − (minus) sign.
  • Students can solve take-away subtraction within 10 using counters and write the matching equation.
  • Students can act out a take-away story with their bodies.
Vocabulary
minussubtracttake awaylessremaining

Lesson plan

Warm-up

5 min

Read-aloud: Grace Lin's 'A Big Mooncake for Little Star' (the first 4 pages, where Little Star takes a bite of the mooncake each night). After reading: 'Little Star started with a whole mooncake. She ate pieces each night. The mooncake got SMALLER. We are going to learn about taking away.'

Teacher moves
  • Show the book illustrations during the read-aloud
  • Pause and ask: 'Was there more mooncake at the START or at the END?' (Affirm: less at the end.)
  • Connect: 'In math we have a sign for taking-away. Let's meet it.'
Media
M-K-S-AT-07-B Video Physical / non-image

Animated illustration in the style of Grace Lin's 'A Big Mooncake for Little Star.' A round golden mooncake sits on a dark night-sky background. Little Star (a small cute cartoon star figure) takes a small bite. The mooncake loses a small wedge. Then another night — another bite. Counter overlay: 'Whole mooncake.' → 'Mooncake minus one bite.' → 'Mooncake minus two bites.' Music: gentle Asian-influenced strings. End on text 'Subtraction = taking away.' Style: watercolor in Grace Lin's palette.

Direct instruction

8 min

Yesterday we joined parts together. Today we go the OTHER way — we take parts away. Watch: I have 8 yellow counters. (Show.) Now I TAKE AWAY 3 of them. (Physically move 3 to the side.) How many are LEFT? Let me count. 1, 2, 3, 4, 5. Five counters left. I write this with a NEW sign — the MINUS sign. (Hold up sandpaper −.) The minus sign means TAKE AWAY. So I write: 8 − 3 = 5. Read with me: 'Eight minus three equals five.' Now look at the number bond. The whole is 8. One part is the 3 I took away. The other part is the 5 left. Same idea — number bond and equation say the same thing.

Key examples
  • Seven MINUS two EQUALS five.
    model 7 − 2 = 5. Number bond 7 / 2, 5.
    prompt Story: 7 birds on a fence. 2 fly away. How many left?
  • Nine MINUS four EQUALS five.
    model 9 − 4 = 5.
    prompt Counters: start with 9 red. Remove 4. How many remain?
  • Six MINUS three EQUALS three. The rekenrek SHOWS the subtraction.
    model 6 − 3 = 3.
    prompt Rekenrek: slide 6 to left, slide back 3 to right.
Checks for understanding
  • Point to − on MG-5. What does this sign tell us to do? (Listen for 'take away' / 'subtract'.)
  • Show me 6 − 2 with your counters. (Watch for: place 6, remove 2, count 4 remaining.)
Media
M-K-S-AT-07-A Illustration
Three side-by-side 6-inch panels labeled C, P, A. Panel C: photograph of 8 yellow two-color counters; 3 are circled and

Three side-by-side 6-inch panels labeled C, P, A. Panel C: photograph of 8 yellow two-color counters; 3 are circled and moved off to the side with an X. Panel P: number bond — 8 on top, 3 in left part-circle (with X), 5 in right part-circle. Panel A: equation '8 − 3 = 5' in 36-pt black marker. Arrows between panels labeled 'TAKE AWAY' and 'WRITE'. Style: clean, primary colors.

Guided practice

10 min
Tasks
  • Pairs work through take-away tasks: (a) Start with 8 counters, take away 5. How many left? (b) Start with 9, take away 4. (c) Start with 7, take away 2. Build with counters AND write the equation.
    scaffold Story-problem mat with START / TAKE-AWAY / RESULT zones.
  • Body subtraction: 8 children stand on the rug. 3 sit down (taken away). 'How many standing?' (5.) Write the equation 8 − 3 = 5 on the floor with chalk.
    scaffold Repeat with different starting counts.
Media
M-K-S-AT-07-C Manipulative Physical / non-image

Laminated 11x17 inch mat. Top section labeled 'START' with a circle holding 8 yellow counters. Middle section labeled 'TAKE AWAY' with a − sign and an arrow pointing toward a 'discard zone' off the mat. Right section labeled 'RESULT' with the equation strip '___ − ___ = ___'. Style: high-contrast (yellow START zone, red TAKE-AWAY zone, green RESULT zone).

Formative assessment

2 min
Exit ticket
  • Write a subtraction equation that matches: 'I had 6 cookies. I ate 2. How many left?'
  • Read the equation aloud.
scoring Correct equation + reading = mastery; one of two = practicing; neither = reteach

Closure

Moves
  • Math Detective close: 'Now we know BOTH + and − signs. Tomorrow we explore: when something is TAKEN AWAY in a story problem, how do we know?'

Homework

5 min
Tasks
  • Find a take-away story at home. Tell a grown-up: 'I had 7 grapes. I ate 3. I have 4 left.' Draw and write the equation.

Exercises in this lesson

math.gK.s.ex_18
Place 8 yellow counters on the rug. TAKE AWAY 3. How many are left?
 take away counters · diff 2
math.gK.s.ex_19
Draw 7 cookies. CROSS OUT 4 of them. How many are left? Write the equation.
 draw subtract · diff 2
math.gK.s.ex_20
Fill in: 9 - 4 = ___
 write subtract equation · diff 2

Differentiation

Scaffolds
  • Pre-printed equation strips (___ − ___ = ___)
  • Cross-out style — child crosses out the taken-away counters with a dry-erase marker
  • Sandpaper − sign for tactile practice
Extensions
  • Missing-addend subtraction: 5 + ___ = 8 reframed as 8 − ___ = 5
  • Subtract three values: 10 − 2 − 3 = 5
English Learners
  • Bilingual sign card (− = menos / minus)
  • Picture-rich take-away cards
  • Audio anchor read-aloud
Ieps 504s
  • Concrete-only response
  • Reduce range (within 5 first)
  • Color-coded take-away (the removed counters turn a different color)

Teacher notes

First subtraction lesson. Grace Lin's mooncake read-aloud is the cultural-context entry — a Chinese-American children's book using the decreasing-whole as the literary device. Critical: do NOT introduce missing-addend subtraction today (8 − ? = 3); start with take-away only, the most concrete subtraction interpretation. Missing-addend appears in lesson 8 (Separate Result Unknown) and again in lesson 11 (Part-Part-Whole Part Unknown). The − sign confuses some children because it looks like just a 'line' — show them the sandpaper sign and have them trace it. Common Day-7 error: adding instead of subtracting (sign confusion); address by always reading the sign aloud before solving.