지도서 · Topic 5 · 5 / 5

Add and subtract within 2020 이내 덧셈과 뺄셈

Facts she can use quickly.

Step 5워크북 12–13쪽 →
한국어 요약

20 이내 덧셈과 뺄셈을 손가락으로 세지 않고 빨리 떠올리게 돕는 영어 대본이에요. 같은 수 두 번 더하기(doubles), 10과 20 만들기, 식 하나에서 네 식 찾기, 등호(=)의 뜻을 질문과 놀이로 연습해요.

이 주제의 단어double
이 주제 차례 (8)

The big idea핵심

Lia should know adding and subtracting facts within 20 quickly, and use clever ways, not only counting. Three ideas help a lot: doubles (7 + 7 = 14), bonds to 10 and 20 (13 + 7 = 20), and facts that go together (if 8 + 7 = 15, then 15 − 7 = 8). The = sign means “is the same as”, so 14 = 7 + 7 is correct too.

13 + 7 = 20: fill the second ten
double 7 = 14

Get ready준비물

  • Two ten frames and 20 counters
  • Two dice
  • Playing cards (Ace to 10)

Teach it, step by step단계별 수업

YOU 부모가 할 말LIA 아이가 할 만한 대답DO 손으로 할 일

Doubles

YOU“Show me 5 fingers on each hand. 5 + 5?”
LIA10.
YOU“That's a double. Double 6? Double 7? Double 8?”
LIA12, 14, 16.

Doubles to 10 + 10 should become instant. They help with near doubles: 7 + 8 = 7 + 7 + 1 = 15.

Bonds to 20

YOU“We know 3 + 7 = 10. So what is 13 + 7?”
LIA20.
YOU“How do you know?”
LIA13 is 10 and 3. 3 and 7 make 10. 10 and 10 make 20.

Facts that go together

YOU“If 8 + 7 = 15, what is 15 − 7?”
LIA8.
YOU“And 15 − 8?”
LIA7.
YOU“One fact gives us four facts!”

The = sign

YOU“Is 14 = 7 + 7 true or false?”
LIATrue.
YOU“Yes. The = sign means both sides are the same. The answer can be on the left or the right.”
광고

Other ways to say it다른 표현

  • “What is double 7?”
  • “What is 8 add 7?”
  • “What is 15 take away 7?”
  • “What do I add to 13 to make 20?”
  • “How many more to make 20?”
  • “What is 3 less than 12?”
  • “What is the total of 9 and 6?”
  • “Is it true or false?”
  • “What is the missing number?”

Good questions to ask좋은 질문

  • “How did you work it out?”

    Note

    Listen for clever ways: doubles, make 10, facts that go together.

  • “Can you find a quicker way?”

    Note

    For 9 + 6: 9 + 1 + 5 = 15.

  • “If you know 6 + 6 = 12, what is 6 + 7?”

    Note

    Near double: 13.

  • “Is 20 − 0 = 0 true?”

    Note

    False: taking away nothing leaves 20.

If Lia is stuck막힐 때

  • When

    She counts on fingers for every fact.

    That's OK at first. Then teach one strategy at a time: doubles first, then make 10.

  • When

    She takes away the wrong way: 7 − 15.

    “Start with the whole, the biggest number.”

  • When

    She thinks = means “the answer comes next”.

    Show both: 7 + 7 = 14 and 14 = 7 + 7. Use a balance picture: both sides the same.

Games (3)놀이

Game · Double trouble

You need: one dice

  1. Roll the dice. Say the double: roll 4 → “double 4 is 8”.
  2. Then say double plus one: “4 + 5 is 9”.
Game · Make 20 cards

You need: playing cards Ace to 10 (Ace = 1)

  1. Turn over two cards. Add them. Then say how many more to make 20: “8 + 5 = 13. 13 and 7 make 20.”
  2. If the total is over 10, subtract the smaller card from the total too: “13 − 5 = 8.”
Game · Dice facts race

You need: two dice, paper

  1. Roll two dice. Add them. Write the fact and one related fact: 5 + 6 = 11 and 11 − 6 = 5.
  2. How many can you write in 2 minutes?

Extra challenge더 도전

  • Three numbers: 7 + 3 + 8 = 18 (make 10 first!).
  • Missing numbers both sides: 9 + ? = 20 − 4.
  • Facts with tens: if 7 + 8 = 15, then 70 + 80 = 150.
In the workbook

Doubles, bonds to 20, true or false, and stories.

워크북 12–13쪽 보기이 주제 인쇄

자주 묻는 질문

doubles가 뭔가요?

같은 수를 두 번 더하는 식이에요. 7 + 7 = 14처럼요.

등호(=)는 영어로 어떻게 설명하나요?

“is the same as”, 곧 양쪽의 값이 같다는 뜻이라고 말해 줘요. 그래서 14 = 7 + 7도 맞는 식이에요.

광고