지도서 · Part 8 · 9 / 10

10 more, 10 less, and adding 10s10 큰 수 · 10 작은 수, 몇십 더하고 빼기

52 + 10 = 62. 76 − 40 = 36.

Step 13워크북 15–16쪽 →고침 2026.11.05
한국어 요약

52보다 10 큰 수(10 more)와 86보다 10 작은 수(10 less)를 십 모형으로 보여 주고, 십의 자리 숫자만 바뀌는 것을 아이가 직접 보게 해요. 그다음 3 + 4 = 7을 써서 30 + 40 = 70을 풀고, 76 − 40처럼 두 자리 수에서 몇십을 더하고 뺄 때 낱개는 그대로 두는 방법을 수직선의 큰 뛰기 하나로 보여 줘요.

이 주제의 단어tens digittensrelated facts
이 주제 차례 (8)

The big idea핵심

10 more means one more ten. 52 is 5 tens and 2 ones. Add one rod: now there are 6 tens and 2 ones. 52 + 10 = 62. Only the tens digit changed. The ones stay the same.

10 less means one ten fewer. 86 − 10: take away one rod. 8 tens become 7 tens. The 6 ones stay. 86 − 10 = 76, not 85. A common mistake is to take away one cube instead of one rod.

Adding 10s uses a fact Lia knows. 3 + 4 = 7, so 3 tens + 4 tens = 7 tens: 30 + 40 = 70. For 76 − 40, take 4 tens from 7 tens. The 6 ones stay: 76 − 40 = 36. On a number line, this is one big jump of 40, not four small jumps.

+
52 + 10: one more rod, the 2 ones stay
86 − 10: take away one rod, not one cube
304050607080+40
30 + 40 = 70: one jump of four tens
3036405060707680−40
76 − 40 = 36: jump back 40, the 6 ones stay

Get ready준비물

  • Base 10 blocks — or make them: bundles of 10 straws with a rubber band, and single straws
  • A Tens | Ones table: draw a line down the middle of a sheet of paper
  • A number line 0–100, or a ruler

Teach it, step by step단계별 수업

YOU 부모가 할 말CHILD 아이가 할 만한 대답DO 손으로 할 일

One more ten

DOShow 52 in the Tens | Ones table: 5 rods and 2 cubes.
YOU“Add one rod. What number is it now?”
CHILD62. There are 6 tens now.
YOU“What changed? What stayed the same?”
CHILDThe tens changed. The 2 ones stayed.
YOU“Yes! 62 is 10 more than 52. Only the tens digit changed.”

Let Lia see it with the blocks first. Say “tens digit” after.

One ten fewer

DOShow 86: 8 rods and 6 cubes.
YOU“What is 10 less than 86?”
CHILD85?
YOU“Let’s check. Take away 10. Is 10 a cube or a rod?”
CHILDA rod! So 76.
YOU“How do you know?”
CHILD76 and 10 make 86.

Taking away one instead of ten is a very common mistake. Let the blocks show it.

Use a fact you know

YOU“What is 3 + 4?”
CHILD7.
DOPut 3 rods and 4 rods together.
YOU“So what is 30 + 40?”
CHILD70. 3 tens and 4 tens make 7 tens.

Keep the ones

DOShow 76: 7 rods and 6 cubes. Point to 76 on the number line.
YOU“Take away 40. How many rods go?”
CHILD4 rods. 3 tens are left.
YOU“And the ones?”
CHILDThe 6 ones stay. So 36.
DODraw one big jump back from 76 to 36.

If she says 30, ask: “Where did the 6 cubes go?”

광고

Other ways to say it다른 표현

  • “What is 10 more than 52?”
  • “What is 10 less than 86?”
  • “Which digit changes?”
  • “Add one ten. Take away one ten.”
  • “Add 3 tens. Subtract 4 tens.”
  • “Use a fact you know.”
  • “The ones stay the same.”
  • “Jump back 40 on the number line.”

Good questions to ask좋은 질문

  • “What is 10 more than 47? Which digit changed?”

    Good answers

    “57. The tens digit changed. The 7 stayed.”

  • “Is 10 less than 86 the same as 1 less than 86?”

    Note

    No. 10 less is 76, 1 less is 85.

  • “You know 5 + 2 = 7. What else do you know?”

    Good answers

    “50 + 20 = 70. 70 − 20 = 50.”

  • “What is 10 more than 90?”

    Note

    100. Ten tens make a hundred — a new digit appears.

If Lia is stuck막힐 때

  • When

    She takes away one: “10 less than 86 is 85.”

    “Is 10 a cube or a rod?” Take away one rod together. Look at the ones: they did not change.

  • When

    She forgets the ones: 76 − 40 = 30.

    “76 has 6 ones. Did we take any ones away?” Point to the 6 cubes that stay.

  • When

    She writes 30 + 40 = 700.

    “3 tens and 4 tens make how many tens?” Show 7 rods. 7 tens is 70.

Game놀이

Game · Ten up, ten down

You need: nothing at all, or a number line 0–100

  1. One player says a 2-digit number: “43.”
  2. The other player says 10 more and 10 less: “53 and 33.”
  3. Say which digit changed. Then swap. Extra: try 30 more!

Extra challenge더 도전

  • 10 more than 95 is 105. 10 less than 104 is 94.
  • Missing tens: 48 + □ = 78. 65 − □ = 25.
  • Two jumps: 23 + 30 − 10 = 43.
In the workbook

10 more and 10 less with base 10 blocks, then add and subtract 10s on a number line.

워크북 15–16쪽 보기이 주제 인쇄

자주 묻는 질문

10 more는 무슨 뜻인가요?

십이 하나 더 있는 수, 곧 10 큰 수예요. 52 + 10 = 62처럼 십의 자리 숫자만 하나 커지고 일의 자리는 그대로예요.

86보다 10 작은 수를 85라고 하면요?

막대 하나 대신 낱개 하나를 뺀 실수예요. 막대 하나를 빼면 8 tens가 7 tens가 되고 6 ones는 그대로라서 76이에요.

76 − 40은 어떻게 푸나요?

7 tens에서 4 tens를 빼면 3 tens가 남고 6 ones는 그대로예요. 76 − 40 = 36이에요. 수직선에서는 40만큼 큰 뛰기 한 번이에요.

광고