Number and Place Value | Mathematics for Grade 4 PDF Download

Place Value System

The place value system helps us understand the value of each digit in a number. Let's take the number 567,891 as an example.

• Ten Thousands Place: The digit 5 is in the ten thousands place, which means it represents 50,000.
• Thousands Place: The digit 6 is in the thousands place, so it represents 6,000.
• Hundreds Place: The digit 7 is in the hundreds place, indicating 700.
• Tens Place: The digit 8 is in the tens place, so it stands for 80.
• Ones Place: Finally, the digit 9 is in the ones place, representing 9.

By understanding the place value system, we can easily determine the value of any digit in a number.

Rounding Numbers

Rounding numbers helps us simplify them to make calculations and estimations easier. We can round a number to the nearest 10, 100, 1000, or even 10,000. Let's round the number 3,827 to the nearest:

• 10: The nearest 10 to 3,827 is 3,830.
• 100: The nearest 100 to 3,827 is 3,800.
• 1000: The nearest 1000 to 3,827 is 4,000.
• 10,000: The nearest 10,000 to 3,827 is also 4,000.

Rounding helps us simplify numbers without losing too much accuracy.

Hindu-Arabic Numerals and Roman Numerals

We use Hindu-Arabic numerals (0, 1, 2, 3, 4, 5, 6, 7, 8, 9) in our daily lives. But did you know that there was a time when people used Roman numerals too? Let's learn about Roman numerals up to 100:

• I represents 1.
• V represents 5.
• X represents 10.
• L represents 50.
• C represents 100.

Now, we primarily use Hindu-Arabic numerals as they are more convenient and versatile.

The Concept of Zero and Negative Numbers

• Zero plays a significant role in our number system. It acts as a placeholder, representing the absence of a value. Without zero, our number system would not function efficiently.
• Negative numbers help us represent quantities below zero. For example, if you owe someone money, the amount you owe would be represented by a negative number. Negative numbers are essential in solving real-life problems.

Let's solve a word problem involving negative and increasingly large positive numbers:

Problem: Sarah has 5 candies, but she eats 3. How many candies does she have left?
Solution: We start with 5 candies and subtract 3 candies (as Sarah ate them). 5 - 3 equals 2. Therefore, Sarah has 2 candies left.