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Multiplication is basic knowledge in mathematics that children will be familiar with, learn about and practice in grade 2. Not only is it applied in mathematics, but this knowledge is also used in many areas of learning and practice. So to better understand what multiplication is called? The secret to learning multiplication effectively, let’s explore more clearly with Nguyễn Tất Thành in the following article.

What is multiplication called?

In mathematics, multiplication is one of the four basic operations of arithmetic along with addition, subtraction and division. In particular, multiplication is the operation of finding the result of 2 or more numbers by repeated additions of those numbers.

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For example 4 + 4 + 4 + 4 = 16. But when we use multiplication, the calculation will be faster when taking 4 x 4 = 14 (meaning the first factor is the term, and the second factor is the quantity). number).

The multiplication formula will be axb = c

In there:

Note: When we multiply 2 numbers, the result we get is called the product. The number of terms in each group will be called the “multiplier” (or second factor) and the number of such equal terms will be called the multiplier.

Properties of multiplication

In basic math knowledge, multiplication will have the following properties:

1. Commutative property of multiplication

ab = ba

This means: When we change the places of the factors in a product, the product remains unchanged.

2. Associative property of multiplication

(ab).c = a.(bc)

Meaning: To multiply a product of two numbers by a third number, we can multiply the first number by the product of the second number and the third number.

3. The distributive property of multiplication over addition

a.(b + c) = ab + ac

Meaning: To multiply a number by a sum, we can multiply that number by each term of the sum, then add the results.

4. Multiply by number 1

a.1 = 1.a = a

Meaning: The product of a number with 1 is equal to that number itself.

Attention:

• The product of a number with 0 is always 0.
• If the product of two factors is 0, then at least one factor is 0.

Common types of multiplication operations

In the basic mathematics program, multiplication will have the following calculation methods:

1. Set normality

Normal calculation is the most basic method when performing multiplication between 1 number and 1 number, 2 numbers and 1 number, 2 numbers and 2 numbers, etc. Here, we will perform multiplication horizontally or vertically. vertical row, make sure to multiply the first factor by each digit of the second factor to create partial products, then add the partial products together to give the final answer.

For example: 268 × 7 = 1876

Or

2 6 8

×

7

———

1 8 7 6

• Units place: 8 times 7 equals 56, write 6 and remember 5 (to tens place)
• Tens: 6 times 7 plus 5 equals 47, write 7 and remember 4 (to hundreds place)
• Hundreds: 2 times 7 plus 4 equals 18, write 18. The result is 1876.

2. Multiply decimals

To perform multiplication of 2 decimal numbers, we will multiply as integers (no need to line up commas if calculating vertically). Next, we will count how many digits the sum of the two factors has in the decimal part. Analyzing the product will have that many digits in the decimal part.

For example: 12.8 x 1.53 = 19.584

First we will multiply the two integers 128 x 153. Because the original 2 factors have 3 decimal places, the result will be 19584. We move the decimal point back 3 places, so the result will be 19,584.

3. Exponentiation

4. Multiplication of fractions

To multiply fractions, we multiply the numerators together and the denominators together.

Common types of exercises related to multiplication

In the basic mathematics program at level 1, children will be introduced to the following types of multiplication exercises:

Form 1: Perform calculations

This is the most basic form of exercise shown in the form of mental calculation in horizontal lines or calculation and then calculation in vertical lines. In it, children will learn:

• Multiplication of 2 digits without remembering: With this calculation, children will perform calculations from right to left. For example: 20 x 3 = 60

• Multiplication of 3 digits without remembering: The children will also do it in turn from right to left, that is, they will calculate from the units place. For example: 124 x 2 = 248

• Multiplication with memory: This is a more advanced form of multiplication exercise, we will also do it in turn from right to left. For each row that has memory, we will write the units place and then add it to the previous row to perform. similar calculation. For example: 156 x 6 = 936.

Type 2: Math puzzle with solution

With this type of exercise, you will have to read the question carefully to know the data and analyze the requirements to determine the correct calculation.

For example: Lan has 6 candies. Hoa has 4 times as much candy as Lan. How many candies does Hoa have?

→ Answer: Hoa has the number of candies: 6 x 4 = 24 (candies)

Form 3: Evaluate expression with multiplication

This exercise will give an expression with many different calculations. So we will have to apply the rule:

• If the expression has parentheses, evaluate the result in the parentheses first
• When an expression has combined addition, subtraction, multiplication, and division operations, calculate the multiplication and division results first, then calculate the addition and subtraction results.
• Expressions that contain only multiplication, division, or only addition or subtraction are calculated from left to right.

Example: Calculate the value of the expression 3 x 2 + 5 + (2 x 6)

→ Answer: 3 x 2 + 5 + (2 x 6) = 3 x 2 + 5 + 12 = 6 + 5 + 12 = 23.

Form 4: Find x

This type of exercise will give an expression with the x value hidden. Your task will be to determine the role of x in the expression and begin calculations to find that value. If you want to find X as an unknown factor, you need to multiply the product by the known factor.

For example: find x and know X : 6 = 9

→ Answer: x = 9 x 6

X = 54

Secrets to help children learn, remember and apply multiplication knowledge effectively

To help children learn multiplication well, parents can apply some of the following tips:

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At the same time, with more than 400 lessons, more than 10,000 interactive activities at Nguyễn Tất Thành Math will help your child practice mathematical thinking effectively, and at the same time, he will easily solve mathematical problems on his own, not simply solve math.

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Children need to memorize the multiplication tables

One of the foundations when learning multiplication is the multiplication table, as well as the first lesson of this calculation.

Therefore, parents need to ensure that their children can memorize the multiplication table depending on their learning ability. You should not force your child to memorize all 9 multiplication tables at the same time. Instead, only learn 1 table at a time until your child learns and remembers it before moving on to the next tables.

At the same time, parents should check their child’s multiplication table regularly to avoid the situation where the child learns by rote and forgets later.

Organize math games for children

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Learning math in general and multiplication in particular for children will be less boring when parents apply teaching methods through games.

Here, parents can invest in math toys sold on the market, or can organize their own games with supporting tools such as familiar objects, or organize small competitions between children. members with attractive rewards….

Changing this method will help children become more interested, increase their ability to remember, understand and apply in learning and life more effectively.

Practice with your child and practice regularly

Besides understanding the theory of multiplication, to make sure your child understands the knowledge, parents should ask them to practice and do exercises regularly.

In addition to the exercises on the textbook and the exercises given by teachers, parents can find many documents, exam questions, and exercises from basic to advanced. Thereby helping children to try many types of exercises, as well as reduce boredom when repeating knowledge in textbooks.

Summary of some multiplication exercises for children to practice

Below are some multiplication exercises that Nguyễn Tất Thành compiled for parents to practice with their children:

Lesson 1: Calculate then calculate

a) 15 x 81

b) 341 x 20

c) 746 x 18

d) 421 x 89

Lesson 2: Calculate the value of the expression ax 99 with a equal to 35, 40, 45

Lesson 3: Find what you know

a) y : 12 = 24

b) y : 57 = 11

c) y : 11 = 999

d) y : 72 = 18

Lesson 4: A 24-book comic book set costs 36,000 VND for each book. How much does that comic cost?

Lesson 5: Farm A, promoting increased production, the first phase consists of 12 days, each day planting 675 rubber trees. Phase 2 is 16 days, each day planting 826 more trees. After those two batches, how many rubber trees did the farm plant in total?

Lesson 6. One week the chickens eat 60 kg of rice. How many kilograms of rice will the chicken eat after 1 month?

Lesson 7. Linh bought 10 notebooks for 15 thousand VND each, 8 pens for 5 thousand VND each. How much money does An have to pay?

Lesson 8. A house has 1 hectare of land with 50 rows of trees, each row has 459 seedlings. The gardener sold 8 rows. How many seedlings are left?

Lesson 9. Evaluating expressions

a) 11278 x 7 + 923 – 824

b) 82892 – 57839 + 580 x 4

c) 9896 : 4 x 10 + 73

d) 8278 x 2 : 3 – 1027

Lesson 10: Perform the following calculation:

a) 1625 x 30

b) 18481 x 11

c) 858 x 100

d) 57 x 1000

Conclude

Above is a summary of basic knowledge about multiplication. This is considered an important foundation that everyone needs to master, especially children, to support their learning and application in real life, accurately. Hopefully the tips that Nguyễn Tất Thành shares will help your child learn more effectively.

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