First of all what is a quadratic equation?

A quadratic equation is any equation that you can write it in the form of $ax^2+bx+c=0$. For example, $x^2+x+5=0$. Next, how to solve this equation.

There are some methods to solve this type of quadratic equations. One of the main methods is to use quadratic formula.

The quadratic formula: $\dfrac{-b\pm \sqrt{b^2-4ac}}{2a}$ gives us the solutions. There are some important points:

• If $b^2-4ac$ is negative, there is no solution.
• If $b^2-4ac =0$, we have only one solution.
• If $b^2-4ac$ is positive, we have two solutions.
• The sum of solutions is: $\dfrac{-b}{a}$
• The product of solutions is : $\dfrac{c}{a}$.

## Math tricks for 3 to 7 year olds

Most parents think that starting to teach math to their children, like any other job, requires backgrounds and that children should reach an age where they can understand the basics of math!
Therefore, they are kind of afraid and prefer to leave this serious responsibility to their child’s preschool and elementary school teachers, and they prefer not to leave a bad effect of mathematics in their child’s mind until they reach the age of 6 or 7, so that they can kick him out of mathematics.

Most parents teach their children the alphabet from the age of 3 or 4, so that when their beloved child enters school, he or she is a head and neck taller than the other children and the teachers see him or her as smarter and smarter!
But the interesting thing is that almost none of the parents have this obsession with teaching math to their child before preschool age!

Unfortunately, this group of parents should know that the best age to teach math to their beloved child is the age of 3 to 7 years, which they unfortunately miss!

## The importance of teaching math to children

Research by reputable institutions around the world has shown that most babies are born with mathematical intelligence, and with this intelligence and their mathematical understanding and analysis, well-trained and on the right track will provide brilliant conditions for children in the future.
Because as you probably know; Most of our lives are tied to understanding and analyzing mathematical problems, and if a person is not able to understand and analyze mathematics, his growth rate and progress in today’s societies will be very slow and close to zero!

Therefore, according to scientists, the best age to start teaching math and understanding the basic concepts of math for children is the same age of 3 to 7 years!

Of course dear parents, It’s not your fault if you neglect this important issue for your child’s education!
Because even the best and most expensive kindergartens and preschools do not spend much time teaching your child math concepts!
Because they still do not understand the importance of learning math at this age can affect the future of the child!

On the other hand, if parents and kindergartens really want to put an end to the development of children’s talents in mathematics, they will be taught to count numbers from 1 to 10 or 1 to 100, and after the child has learned these basics; They feel that they have made him a mathematical scientist!
If learning to count numbers for children is one of the least important and least relevant to understanding the concepts of mathematics!
You teach him to count numbers like learning the letters of the alphabet through poetry and games, but you do not add a bit to his mathematical intelligence and comprehension!

Of course, we still say that in the meantime, it is not the fault of the parents and teachers of the kindergarten, because the right way to teach math concepts to children aged 3 to 7 has not been given to them!

### Trick 1: Multiplying a number by 5

To multiply a number by 5, simply divide the number by 2 and multiply it by 10.

For example, multiply 86 by 5.

Step 1: Divide 86 by 2 = 43

Step 2: Multiply 43 by 10 = 430

This is one of the first and easiest tricks I’ve taught my kids. Once your kids get the hang of it, they’ll take only a moment to find the answer.

### Trick 2: Multiplying a double-digit number by  11

Multiplying any double-digit number by 11 takes only a moment. All you have to do is add up the two numbers and place the sum in between the two numbers.

For example, multiply 54 by 11

Step 1: Add 5 and 4 = 9

Step 2: Place 9 in between 5 and 4 = 594

### Trick 3: Multiplying a number by 6

This trick is only helpful when multiplying even numbers by 6. You will have to divide the number by 2 to get the first digit of the answer. The next digit will be the number you divided 6 with.

For example, multiply 8 by 6

Step 1: Divide 8 by 2 = 4

Step 2: Place 8 after 4 = 48

### Trick 4: Multiplying a number by 9

Once my kids mastered the simple tricks such as those mentioned above, I taught them tricks like this one.

To quickly multiply a number by 9, you should subtract 1 from the number to get the first digit of the answer. Then, subtract this number from 10 to get the second digit of the answer.

For example, multiply 7 by 9

Step 1: Subtract 1 from 7 = 6

Step 2: Subtract 7 from 10 = 3

Step 3: Place the two together = 63

### Trick 5: Squaring a double-digit number ending with 5

Once your kids learn how to square numbers, you could teach them this trick to square numbers ending with 5. What you have to do is add 1 to the first digit of the number (being squared) and multiply the sum to the first digit of the original number (being squared). Your answer will be this answer followed by 25.

For example, square 45

Step 1: Add 1 to 4 = 5

Step 2: Multiply 5 by 4 = 20

Step 3: Place 25 after 20: 2025