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Number Sequence to 20

Kindergarten · Mathematics · Worksheet 2

  1. 9, 10, _, 12, 13 Answer: ______________
  2. What number comes after 1? Answer: ______________
  3. 11, 12, _, 14, 15 Answer: ______________
  4. What number comes after 9? Answer: ______________
  5. 17, 18, _, 20 Answer: ______________
  6. Matiu is counting his toy cars. He says: 14, 15, 16, __, 18. What number is missing? Answer: ______________
  7. What comes after 12? Answer: ______________
  8. Look at the pattern: 🟥 🟥 🟥 | 🟥 🟥 🟥 | 🟥 🟥 🟥. How many red squares are there in total? Answer: ______________
  9. Mason is hopping along a path of numbered stones. The stones Mason hops on say: 18, 19, ___. What number is on the missing stone? Answer: ______________
  10. Tane sees a number line on the wall. The numbers go: 1, 2, ____. What is the missing number? Answer: ______________
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Answer Key & Explanations

Number Sequence to 20 · Kindergarten · Worksheet 2

  1. 9, 10, _, 12, 13 Answer: 11 Solution: Look at the sequence: 9, 10, _, 12, 13. Count forward from 9: 9, 10, 11, 12, 13. The missing number between 10 and 12 is 11.
    Full step-by-step solution

    Step 1: Look at the sequence: 9, 10, _, 12, 13. Step 2: Count forward from 9: 9, 10, 11, 12, 13. Step 3: The missing number between 10 and 12 is 11. The answer is 11.

  2. What number comes after 1? Answer: 2 Solution: When counting up, the number after 1 is 2.
  3. 11, 12, _, 14, 15 Answer: 13 Solution: Look at the sequence: 11, 12, _, 14, 15 From 11 to 12 is +1 From 14 to 15 is +1 The missing number should be 12 + 1 = 13 Check: 11, 12, 13, 14, 15 - this makes a complete counting sequence The answer is 13.
    Full step-by-step solution

    Step 1: Look at the sequence: 11, 12, _, 14, 15 Step 2: Notice the numbers are counting forward Step 3: From 11 to 12 is +1 Step 4: From 14 to 15 is +1 Step 5: The missing number should be 12 + 1 = 13 Step 6: Check: 11, 12, 13, 14, 15 - this makes a complete counting sequence The answer is 13.

  4. What number comes after 9? Answer: 10 Solution: When counting up, the number after 9 is 10.
  5. 17, 18, _, 20 Answer: 19 Solution: Look at the sequence: 17, 18, _, 20. Count forward from 17: 17, 18, 19, 20. The missing number is 19.
    Full step-by-step solution

    Step 1: Look at the sequence: 17, 18, _, 20. Step 2: Count forward from 17: 17, 18, 19, 20. Step 3: The missing number is 19. The answer is 19.

  6. Matiu is counting his toy cars. He says: 14, 15, 16, __, 18. What number is missing? Answer: 17 Solution: Start at 14 and count forward: 14, 15, 16, ... Step 2: The next number after 16 is 17. Step 3: Check: 14, 15, 16, 17, 18.
    Full step-by-step solution

    Step 1: Start at 14 and count forward: 14, 15, 16, ... Step 2: The next number after 16 is 17. Step 3: Check: 14, 15, 16, 17, 18. The missing number is 17. The answer is 17.

  7. What comes after 12? Answer: 13 Solution: Start counting from 12. The next number in the counting sequence is 13.
    Full step-by-step solution

    Step 1: Start counting from 12. Step 2: The next number in the counting sequence is 13. The answer is 13.

  8. Look at the pattern: 🟥 🟥 🟥 | 🟥 🟥 🟥 | 🟥 🟥 🟥. How many red squares are there in total? Answer: 9 Solution: Identify the groups. The vertical bars "|" separate the squares into groups. - First group: 🟥 🟥 🟥 → 3 red squares - Second group: 🟥 🟥 🟥 → 3 red squares - Third group: 🟥 🟥 🟥 → 3 red squares Add the number of squares in each group.
    Full step-by-step solution

    Let's break down the problem step by step. We see the pattern: 🟥 🟥 🟥 | 🟥 🟥 🟥 | 🟥 🟥 🟥 Step 1: Identify the groups. The vertical bars "|" separate the squares into groups. - First group: 🟥 🟥 🟥 → 3 red squares - Second group: 🟥 🟥 🟥 → 3 red squares - Third group: 🟥 🟥 🟥 → 3 red squares Step 2: Add the number of squares in each group. 3 + 3 + 3 = 9 Step 3: Verify by counting all squares without grouping. If we ignore the bars, there are 9 red squares in a row: 🟥 🟥 🟥 🟥 🟥 🟥 🟥 🟥 🟥. Counting them one by one also gives 9. Step 4: Conclusion. The total number of red squares is 9.

  9. Mason is hopping along a path of numbered stones. The stones Mason hops on say: 18, 19, ___. What number is on the missing stone? Answer: 20 Solution: See the numbers on the stones Mason hopped on: 18 and 19. The numbers go in order, increasing by 1 each time: 18 to 19 is +1. The missing stone comes after 19, so it is 19 + 1 = 20.
    Full step-by-step solution

    Step 1: See the numbers on the stones Mason hopped on: 18 and 19. Step 2: The numbers go in order, increasing by 1 each time: 18 to 19 is +1. Step 3: The missing stone comes after 19, so it is 19 + 1 = 20. The answer is 20.

  10. Tane sees a number line on the wall. The numbers go: 1, 2, ____. What is the missing number? Answer: 3 Solution: Look at the two numbers we know: 1 and 2. The numbers go up by 1 each time. From 1 to 2 is +1.
    Full step-by-step solution

    Step 1: Look at the two numbers we know: 1 and 2. Step 2: The numbers go up by 1 each time. From 1 to 2 is +1. Step 3: So the missing number must be 2 + 1 = 3. The answer is 3.