지도서 · Part 5 · 6 / 8

Add and subtract 1s일의 자리 더하고 빼기

34 + 3 = 37. Only the ones change.

Step 5워크북 11쪽 →
한국어 요약

34 + 3 = 37처럼 일의 자리만 바뀌는 덧셈과 뺄셈을 영어로 가르치는 법이에요. tens digit, ones digit이라는 말과 자릿값 생각을 블록으로 보여 주고, 10을 넘지 않는 수로 연습해요.

이 주제 차례 (8)

The big idea핵심

When we add or take away a few ones, and the ones do not go past 10, only the ones digit changes. The tens stay the same. For example: 34 has 3 tens and 4 ones. 4 ones + 3 ones = 7 ones. So 34 + 3 = 37. This is about place value: the tens digit and the ones digit have different jobs.

+
34 + 3 = 37

Get ready준비물

  • Lego towers of 10 and single bricks
  • A pencil and paper
  • Numbers where the ones do not pass 10 (like 42 + 5 or 67 − 4). Crossing 10 is the next step!

Teach it, step by step단계별 수업

YOU 부모가 할 말LIA 아이가 할 만한 대답DO 손으로 할 일

Build the number

DOBuild 34 with 3 towers and 4 single bricks.
YOU“How many tens? How many ones?”
LIA3 tens and 4 ones.
YOU“The tens digit is 3. The ones digit is 4.”

Add some ones

DOAdd 3 single bricks.
YOU“What changed? The tens or the ones?”
LIAThe ones.
YOU“How many ones now?”
LIA7.
YOU“So 34 + 3 = 37. The tens digit stayed 3.”

Take away some ones

DOBuild 58. Take away 5 single bricks.
YOU“How many ones are left?”
LIA3.
YOU“Did the tens change?”
LIANo.
YOU“So 58 − 5 = 53.”

Look for the pattern

YOU“41 + 1 = 42. 41 + 2 = 43. 41 + 3 = 44.”
YOU“What do you notice?”
LIAThe ones go up by one. The tens don't change.
YOU“Now 58 − 1, 58 − 2, 58 − 3…”

Only numbers

YOU“Can you do 82 + 7 in your head?”
LIA89.
YOU“How did you do it?”
LIA2 add 7 is 9, and the 8 tens stay.
광고

Other ways to say it다른 표현

  • “What is 3 more than 34?”
  • “What is 5 less than 58?”
  • “34 add 3”
  • “58 take away 5”
  • “What changes: the tens or the ones?”
  • “What is the ones digit now?”
  • “Which digit stays the same?”
  • “Count on 3 from 34.”
  • “Count back 5 from 58.”

Good questions to ask좋은 질문

  • “Which digit changes? Which digit stays the same?”

  • “Why does the tens digit stay the same?”

    Good answers

    “Because we only added ones, and the ones did not make a new ten.”

  • “What is the same about 23 + 4 and 3 + 4?”

    Note

    The ones fact is the same: 3 + 4 = 7.

  • “Is 64 + 4 = 104 true?”

    Note

    False. It is 68. Only the ones change.

If Lia is stuck막힐 때

  • When

    She adds to the tens: 34 + 3 = 64.

    “Is it 3 ones or 3 tens?” Build it. Single bricks are ones.

  • When

    She counts on in ones from 1.

    “Start at 34. Put 34 in your head. Now count on 3: 35, 36, 37.”

  • When

    She reads 34 as 43.

    Point: “Tens first, then ones.” Build it with towers.

  • When

    You chose a number that crosses 10, like 38 + 5.

    That is the next step. If Lia can do it, great! Show her Part 6: make 10 first.

Games (2)놀이

Game · Number spy

You need: nothing

  1. Say: “I am thinking of a number. It has 5 tens and 2 ones. What is it?” (52)
  2. “Now I add 4 ones. What is my number?” (56)
  3. “Now I take away 3 ones.” (53). Lia makes a number for you next.
Game · Dice ladder

You need: one dice, paper

  1. Start at 21. Roll the dice and add: 21 + 4 = 25. Write it.
  2. Keep going while the ones stay 9 or less. If a roll would pass 10, the other player takes the turn.
  3. Talk about the rule: “Which rolls can we use when we are at 25?” (1, 2, 3, 4)

Extra challenge더 도전

  • Add tens instead: 34 + 30 = 64. “Now what changes?” (The tens.)
  • Two steps: 57 − 4 − 2 = ?
  • Missing numbers: 64 + ? = 68, ? − 3 = 42.
In the workbook

Base 10 pictures, patterns and two stories.

워크북 11쪽 보기이 주제 인쇄

자주 묻는 질문

ones digit은 무엇인가요?

일의 자리 숫자예요. 34에서 ones digit은 4, tens digit은 3이에요.

34 + 3에서 왜 십의 자리는 그대로인가요?

일의 자리끼리 더해도 10을 넘지 않아서요. 4 + 3 = 7이라 37이 돼요.

광고