Meeting the Plus Sign — Addition as Putting Together

Body equation: 5 children stand on the rug in a clump. 3 more children join them. 'How many altogether?' Children count: 8. Teacher narrates: 'We put parts together. We JOINED 5 and 3 to make 8.'

• Hold up the large + card and say 'This sign means PLUS. It means joining parts together.'
• Repeat the body equation with different starting counts (4 + 2, 6 + 3) to build pattern recognition

We have been finding parts of whole numbers. Today we learn how to WRITE what we have been doing. The plus sign (point to MG-5, hold up sandpaper +) — PLUS — means we are PUTTING PARTS TOGETHER. The equals sign (hold up sandpaper =) — EQUALS — means BOTH SIDES ARE THE SAME, like a balance. Watch: I have 5 yellow counters and 3 red counters. (Show.) I write '5 + 3' — that's the EXPRESSION. It tells me what I am joining. Then I count all of them — 1, 2, 3, 4, 5, 6, 7, 8 — and I write '= 8'. The whole equation reads: 'Five plus three equals eight.' Now look at our number bond. The whole is 8. The parts are 5 and 3. The number bond and the equation say the same thing.

• Five PLUS three EQUALS eight.

  model Expression: 5 + 3. Equation: 5 + 3 = 8. Number bond: 8 / 5, 3.

  prompt 5 yellow + 3 red counters → 8 total
• Four plus two equals six. The rekenrek SHOWS the equation.

  model 4 + 2 = 6. Number bond: 6 / 4, 2.

  prompt On the rekenrek: slide 4 red beads then 2 white beads
• Three plus five also equals eight. The PARTS can switch — the WHOLE stays the same. This is the commutative property — but at K we just notice it.

  model 3 + 5 = 8. Same total — order of parts does not change the whole.

  prompt Reverse: 3 + 5 with same counters

• Point to + on MG-5. What does this sign tell us to do? (Listen for 'put together' / 'join' / 'add'.)
• Show me on the rekenrek: 3 + 4. How much altogether? (Slide 3 then 4; child says 7.)

M-K-S-AT-03-A Illustration

Three side-by-side 6-inch panels labeled C, P, A. Panel C (Concrete): photograph of 5 yellow + 3 red two-color counters on a tray. Panel P (Pictorial): number bond drawing with 8 on top, 5 and 3 below. Panel A (Abstract): equation '5 + 3 = 8' in large 36-pt black marker. Connecting arrows between panels with the words 'JOIN' and 'WRITE'. Style: textbook clean, white background.

• Equation-building station: pairs use number cards and sign cards to build addition equations matching counter configurations. 'I built 6 + 2 = 8 with my counters — now build the equation card with the cards.'

  scaffold Provide pre-arranged counter sets with the answer hidden.
• Body equation: in groups of 8 children, divide into a group of 5 and a group of 3 across the rug. Write the matching equation on the floor with chalk: 5 + 3 = 8.

  scaffold Vertical board (Liljedahl VNPS) for equation writing for groups of 4 children at a time.

• Write an addition equation that matches this picture (teacher shows 6 counters: 4 yellow + 2 red): ___ + ___ = ___.
• Read the equation aloud.

• Math Detective close: 'Today we learned how to WRITE adding. Tomorrow we keep adding — with bigger numbers, with the rekenrek, with stories.'
• Show MG-5 once more and ask: 'What does + mean? What does = mean?'

• Find an addition story at home. Tell a grown-up: 'I have 3 forks. My sister has 2 forks. We have 5 forks altogether.' Draw the picture and write the equation.