What is Counting in Tens?

S0-SA1-0267

Grade Level:

Pre-School – Class 2

All domains without exception

Definition

What is it?

Counting in tens means grouping items into sets of ten and then counting how many such groups you have. It's a quick way to count large numbers by adding ten repeatedly, like 10, 20, 30, and so on.

Simple Example

Quick Example

Imagine you have many laddoos for a festival. Instead of counting each one, you put them into plates, with 10 laddoos on each plate. If you have 3 plates full, you quickly know you have 10 + 10 + 10 = 30 laddoos.

Worked Example

Step-by-Step

Let's say you are counting the number of chalk sticks in your classroom. You have a big box full of them.
---Step 1: Take out 10 chalk sticks and make a small bundle with a rubber band.
---Step 2: Repeat this process. Take out another 10 and make a second bundle.
---Step 3: Continue making bundles of 10 until no more full bundles can be made.
---Step 4: Suppose you made 7 such bundles.
---Step 5: To find the total, you count by tens: 10 (first bundle), 20 (second), 30 (third), 40 (fourth), 50 (fifth), 60 (sixth), 70 (seventh).
---Answer: You have 70 chalk sticks.

Why It Matters

Counting in tens is a basic skill that helps you understand place value and quickly estimate quantities. It's essential for future math concepts like multiplication, division, and even handling money. Engineers and business owners use estimation daily to manage resources and budgets.

Common Mistakes

MISTAKE: Counting each item individually instead of grouping them. | CORRECTION: Always try to group items into tens first, then count the groups.

MISTAKE: Forgetting to add the remaining single items if the total isn't an exact multiple of ten. | CORRECTION: After counting full tens, count any leftover items and add them to your total.

MISTAKE: Mixing up counting by tens with counting by fives or ones. | CORRECTION: Ensure you are consistently adding 10 each time you count a new group.

Practice Questions

Try It Yourself

QUESTION: A shopkeeper has 5 packets of biscuits, and each packet has 10 biscuits. How many biscuits are there in total? | ANSWER: 50 biscuits

QUESTION: Your school library received 8 boxes of new storybooks. Each box contains 10 books. How many new storybooks did the library get? | ANSWER: 80 storybooks

QUESTION: Riya is collecting marbles. She has 4 bags, and each bag has 10 marbles. She also has 7 loose marbles. How many marbles does Riya have in total? | ANSWER: 47 marbles (4 bags x 10 marbles/bag = 40 marbles; 40 + 7 = 47 marbles)

MCQ

Quick Quiz

If you count 6 groups of ten, what number do you reach?

600

The Correct Answer Is:

Counting 6 groups of ten means adding 10, six times: 10 + 10 + 10 + 10 + 10 + 10 = 60. So, the correct answer is 60.

Real World Connection

In the Real World

When shopkeepers at a kirana store count money, especially currency notes like Rs. 10 or Rs. 100, they often stack them in bundles of ten to quickly calculate the total amount. This makes counting large sums of money much faster and less prone to errors.

Key Vocabulary

Key Terms

GROUPING: Putting items together in sets | PLACE VALUE: The value of a digit based on its position in a number | ESTIMATE: To make an educated guess about the quantity or value | MULTIPLE: The result of multiplying a number by an integer

What's Next

What to Learn Next

Now that you understand counting in tens, you're ready to learn about place value, which explains how digits like 1, 2, and 3 get their value based on their position (ones, tens, hundreds). This will help you count and understand even larger numbers!