Addition Chapter Notes | Mathematics Class 4 ICSE PDF Download

Introduction

Addition is like gathering your favourite toys or snacks and putting them all together to see how many you have! In this exciting chapter, we’ll dive into the world of adding numbers, from simple single-digit sums to bigger four-digit numbers. We’ll learn cool tricks like adding without carrying over, handling carry-overs, using expanded form, estimating sums, and even solving real-life problems. Get ready to become an addition wizard as we explore each step in a fun and easy way!

Addition of Numbers (without carry over)

• Add numbers step-by-step starting from the ones place, then tens, hundreds, and thousands.
• Write the sum of each place value directly below its column.
• No carry-over is needed if the sum in each column is less than 10.

Addition of Numbers (with carry over)

• Start adding from the ones place.
• If the sum in any column is 10 or more, write the ones digit and carry over the tens digit to the next column.
• Repeat for tens, hundreds, and thousands, adding any carried-over digits.

Addition Facts

• Numbers can be added in any order, and the sum remains the same.
• Adding 0 to any number gives the same number.
• Adding 1 to a number gives the next number.
• A number can be written as the sum of two or more numbers in different ways.

Addition Using Expanded Form

• Write each number in expanded form (thousands, hundreds, tens, ones).
• Add the values for each place separately.
• Combine the sums to get the final result.

Finding the Missing Digits

• Look at each column (ones, tens, hundreds, thousands).
• Find the number that, when added to the known digit, gives the sum in that column.
• If the sum is smaller than the known addend, consider a carry-over from the previous column.
• Subtract to find the missing digit: sum - known addend = missing addend.
• Carry over any tens digit to the next column if needed.

Estimating the Sum

• Round off each number to the nearest 10, 100, or 1,000 based on the required accuracy.
• Add the rounded numbers to get an approximate sum.
• Estimation gives a quick way to check if the actual sum is reasonable.

Solving Word Problems

• Identify the numbers to be added from the problem.
• Add the numbers step-by-step, considering carry-overs if needed.
• Write the final sum as the answer to the problem.

Framing Word Problems

• Create a real-life situation where the given numbers represent quantities to be added.
• Ensure the context is logical (e.g., number of students, money, or items).
• Form a question asking for the total sum.