What is Skip Counting by Threes?

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Grade Level:

Pre-School – Class 2

All domains without exception

Definition

What is it?

Skip counting by threes means counting forward by adding 3 each time to the previous number. Instead of counting every number (1, 2, 3, 4...), you 'skip' two numbers in between and land on every third number.

Simple Example

Quick Example

Imagine you are buying laddoos for a festival. Each box has 3 laddoos. If you buy 1 box, you have 3 laddoos. If you buy 2 boxes, you have 6 laddoos (3 + 3). If you buy 3 boxes, you have 9 laddoos (6 + 3). You are skip counting by threes: 3, 6, 9...

Worked Example

Step-by-Step

Let's find the next three numbers in the sequence: 9, 12, 15, ___, ___, ___.

Step 1: Identify the starting number. It is 9.

Step 2: Understand the pattern. We are skip counting by threes, which means adding 3 to the previous number.

Step 3: Add 3 to the last given number (15). So, 15 + 3 = 18.

Step 4: Add 3 to the new number (18). So, 18 + 3 = 21.

Step 5: Add 3 to the next new number (21). So, 21 + 3 = 24.

Answer: The next three numbers are 18, 21, 24.

Why It Matters

Skip counting by threes builds a strong foundation for multiplication tables and understanding patterns in numbers. It's crucial for quick mental calculations and helps in fields like accounting, where you might quickly estimate costs, or even in sports, like calculating total points if each goal is worth 3 points.

Common Mistakes

MISTAKE: Adding 2 instead of 3, or skipping an incorrect number of steps. For example, going 3, 6, 8, 11... | CORRECTION: Always add exactly 3 to the previous number. Double-check your addition each time.

MISTAKE: Starting the sequence from 1 and then adding 3. For example, starting a sequence by saying 1, 4, 7... when the instruction is to count by threes. | CORRECTION: Skip counting usually starts from the number itself (e.g., 3, 6, 9...) or from a given starting point, not always from 1.

MISTAKE: Forgetting the sequence of numbers and getting stuck. For example, 3, 6, _, 12... | CORRECTION: If you get stuck, you can always count on your fingers or draw three tally marks for each step to help you add correctly.

Practice Questions

Try It Yourself

QUESTION: What are the first five numbers when skip counting by threes, starting from 3? | ANSWER: 3, 6, 9, 12, 15

QUESTION: A bus picks up 3 passengers at each stop. If it has made 6 stops, how many passengers has it picked up in total? (Assume it started empty.) | ANSWER: 18 passengers (3, 6, 9, 12, 15, 18)

QUESTION: You are making garlands, and each garland needs 3 marigold flowers. If you want to make 7 garlands, how many flowers do you need? Show your skip counting sequence. | ANSWER: 21 flowers (3, 6, 9, 12, 15, 18, 21)

MCQ

Quick Quiz

Which of these sequences shows skip counting by threes?

1, 2, 3, 4, 5

3, 6, 9, 12, 15

2, 4, 6, 8, 10

5, 10, 15, 20, 25

The Correct Answer Is:

Option B (3, 6, 9, 12, 15) correctly shows numbers increasing by 3 each time. Options A, C, and D show counting by ones, twos, and fives, respectively.

Real World Connection

In the Real World

In cricket, if a batsman hits only boundaries for fours and sixes, but also gets runs in threes (like running three quick runs), skip counting by threes helps the scorer quickly tally these runs. Imagine a scorekeeper quickly adding 3, 6, 9, 12 to total a player's runs from hitting multiple 'threes' in an over.

Key Vocabulary

Key Terms

Skip Counting: Counting by adding a fixed number each time, skipping intermediate numbers | Sequence: A set of numbers arranged in a particular order | Pattern: A regular and repeatable way in which something happens or is arranged | Addition: The process of combining two or more numbers to find their total

What's Next

What to Learn Next

Once you're comfortable with skip counting by threes, you can explore skip counting by fours and fives. This will further strengthen your understanding of multiplication tables and number patterns, making bigger calculations much easier!