Fun with Numbers — CBSE Class 3 Maths Chapter 2 NCERT Guide

Understanding 3-Digit Numbers

A three-digit number is made up of three places: Hundreds (H), Tens (T), and Ones (O). When we count up to 99, we are using two-digit numbers. But when we add 1 more to 99, we get 100, which is the smallest three-digit number! Imagine you have single blocks (Ones). When you group 10 single blocks together, you get 1 strip of Ten. When you group 10 strips of Ten together, you get 1 big grid of a Hundred. For example, let's look at the number 235: It has 2 Hundreds (200), 3 Tens (30), and 5 Ones (5). Written in expanded form, it is: 200 + 30 + 5 = 235. We read this number as Two hundred thirty-five.

How to Write a Number in Expanded Form

1. Identify the Place of Each Digit — Look at the digits from right to left. The first digit is in the Ones place, the second is in the Tens place, and the third is in the Hundreds place.
2. Find the Value of Each Position — Multiply the Hundreds digit by 100, the Tens digit by 10, and keep the Ones digit as it is.
3. Write as an Addition Equation — Put a plus (+) sign between these values to show the expanded form. For example, for 456, we write: 400 + 50 + 6.

Skip Counting Examples

• Example 1: Counting by 10s. Let's count forward by 10 starting from 110: 110, 120, 130, 140, 150, 160. Notice how only the Tens digit increases by 1 each time.
• Example 2: Counting by 50s. Let's skip count by 50 starting from 200: 200, 250, 300, 350, 400, 450. This is super helpful when counting currency notes!
• Example 3: Counting Backwards by 10s. Let's jump backwards starting from 380: 380, 370, 360, 350, 340.

Be Careful with the Zero (0)!

A common mistake students make is writing the wrong number name for numbers with zero in the tens place. For example, for 305, some students mistakenly write it as Three hundred fifty. Remember, 305 is Three hundred five because there are 0 tens. Three hundred fifty is written as 350 (3 hundreds and 5 tens). Always double-check the place value of zero so you do not lose easy marks!

Practice Questions with Solutions

• Q: Radhika collected 24 seeds, Vicky collected 42 seeds, and Gauri collected 47 seeds. Who collected the most seeds, and how many more seeds does Vicky need to collect to equal Gauri's seeds? A: Step 1: Compare the number of seeds collected: Radhika = 24, Vicky = 42, Gauri = 47. Since 47 is the largest number, Gauri collected the most seeds. Step 2: Find the difference between Gauri's and Vicky's seeds: 47 - 42. Step 3: Calculate the subtraction: 47 - 42 = 5. Final answer: Gauri collected the most seeds. Vicky needs to collect 5 more seeds.
• Q: Write the number name and the expanded form for the number 709. A: Step 1: Identify the place value of each digit. There are 7 Hundreds, 0 Tens, and 9 Ones. Step 2: Write the expanded form: 700 + 0 + 9. Step 3: Write the number name based on the place values: Seven hundred nine. Final answer: Number Name is 'Seven hundred nine' and Expanded Form is 700 + 0 + 9.
• Q: Dhoni is playing on 96 runs. How many runs does he need to complete a century? A: Step 1: Recall that 1 century equals exactly 100 runs. Step 2: Subtract Dhoni's current score from 100 to find the missing runs: 100 - 96. Step 3: Calculate: 100 - 96 = 4. Final answer: Dhoni needs 4 more runs to complete his century.
• Q: Continue the skip counting pattern: 550, 600, 650, ____, ____, ____. A: Step 1: Identify the gap between the numbers: 600 - 550 = 50. So, we are skip counting forward by 50. Step 2: Add 50 to 650 to get the next number: 650 + 50 = 700. Step 3: Add 50 to 700: 700 + 50 = 750. Step 4: Add 50 to 750: 750 + 50 = 800. Final answer: The complete pattern is 550, 600, 650, 700, 750, 800.

Frequently Asked Questions