IMO Class 5 Chapter 4: Multiplication and Division of Decimal Numbers

IMO Class 5 Chapter 4: Multiplication and Division of Decimal Numbers

Mathematics is one of the subject areas in which students must master concepts. Practice is one of the most important aspects of mastering mathematics, and the International Maths Olympiad (IMO) is one such platform where students are trained to understand its fundamentals.

International Maths Olympiad is held by School Connects Online. It is open to students in grades 1 to 10. All of the questions on these exams are multiple-choice. The Olympiad exam also serves as a foundation for students to achieve academic success. It gives students an advantage over their peers when solving difficult questions. This article is all about IMO class 5 chapter 4: Multiplication and division.

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IMO Class 5 Chapter 4: Multiplication and Division of Decimal Numbers Detailed Notes

Decimal Multiplication

Decimal multiplication is done by counting the number of digits to the right of the decimal point. Consider the decimal-free numbers. Write the result after multiplying the integers as usual. Move the decimal after a certain number of digits, equal to the total number of digits after decimal points, now from the correct position.

Take the example 9.2 x 3.14 into consideration. Start by counting the digits that follow the decimal in both numbers. 9.2 has one digit following the decimal, while 3.14 has two digits. Taking both into account, we obtain 92 and 314 as whole numbers. Add these together to get the answer: 92 x 314 = 28888.

Now take a look at the outcome, starting from the right place the decimal after shifting a total of as many positions as the total of the numbers multiplied. Therefore, there are 1 + 2 = 3 spaces. The result is 28.888 if the decimal is placed three positions to the right of the result. Thus 9.2 × 3.14 = 28.888.

Think over the case 2.66 x 1.004 once more. Determine how many digits there are overall after the decimal. In this instance, 2 + 3= 5 . Multiply both of the decimal-free integers to get the total. So, 266 × 1004= 267064. Place the decimal after 5 positions, starting from the right, to get the answer. So, 2.66 × 1.004 = 2.67064.

Decimal division

Students must be familiar with how to arrange decimals for a non-terminating division in order to comprehend the notion of decimal division.

The Decimal Concept for an Incorrect Division

Take 8/3 as an example. We are aware that the remaining is 2 when 8 is divided by 3. Additionally, since 2 is less than 3 it cannot be split. After the quotient, we add a decimal to continue the division. After doing so, we can continue to divide the remaining amount by zeroes. Therefore, 8/3 Equals 2.666, where 6 is repeated.

Comparable to decimal multiplication is decimal division. To make the dividend and divisor entire numbers, multiply them by a suitable quotient. As said previously, divide the whole numbers and add the decimal after the quotient.

Think about the case of 26.6/2.4. Here, add 10 to the dividend and the divisor. As a result, the division is 266/24. However, the division retains its original worth. Execute the division, then get the outcome. 266/24 = 11.0833

Think about another example, 20.04/1.8. Here, we can observe that the decimal places in the numerator and denominator differ. We must multiply the numerator by 100 in order to get it to a whole number. Add 100 to the denominator and numerator. 

We get 2004/180. Divide right away, then get the outcome.

2004/180 = 11.133

Question 1 : Solve the problem 2.6 × 1.3/ 0.8

Answer: Count the total number of digits following decimals in multiplication using BODMAS principles first. The multiplicands are multiplied by two, the decimal is positioned after the second from the right, and the answer is two. 2.6 × 1.3 = 3.38.

We now have 3.38/0.8. Multiplying the numerator and denominator by 100 will make the numerator a full number. The result is 338/80. dividing the total to get the outcome,

338/80 = 4.225

therefore, 2.6 × 1.3 / 0.8 = 4.225

Also Read: How to prepare for Olympiads?

School Connect Online offers olympiads such as:

1.National Science Olympiad (NSO)

2. International Mathematics Olympiad (IMO)

3. Coding Olympiad 

4.Artificial Intelligence Olympiad.

Prepare for your Olympiad coaching with the Olympiad Genius by interacting with one of the greatest educators from IIT, NIT, as well as other institutions!

Related Links : 

IMO Class 1 chapter 1

Science class 5 chapter 8 full details

IMO Class 1 Chapter 7

IMO Class 5 Chapter 1

IMO class 3 chapter 2

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