math-tricks-for-fractions-and-multiplication

We get it, math can be tough. With all the numbers, symbols and functions swirling around, anyone can get dizzy. This especially the case with young children, especially for grade 5 and above students, who are just taking their first steps in the world of complex mathematics. For them the problems of mathematics are further escalated by traditional teaching methods, which can be very boring. To answer both of these problems, let me introduce you to the wonderful world of math hacks! Here we explain math tricks for fractions and multiplication. So, without further ado, let’s get right to it.

Math Tricks For Fractions And Multiplication

The Butterfly Effect

math-tricks-for-fractions-and-multiplication-adding-subtracting-fractions

Adding and Subtracting Fractions

I’m sure students will love this one. One of the things about math that annoys young children is fractions. They seem complicated and difficult to deal with. And heavens forbid if you have to add and subtract them! But that’s where the butterfly method comes to the rescue. So how does it work? Let’s find out!

Step 1:

Let us take some fractions as examples, like 2/3 and 3/5.

math tricks for fractions and multiplication - Butterfly Method

Step 2:

Now in case we have to add the fractions, this is what we do. Take the denominator of the first number, that is 3, and multiply it with the numerator of the second number, that is 3. We will get 9.

 

math tricks for fractions and multiplication - Butterfly Method step 2

Step 3:

Now we do the same thing with the other numerator and denominator, that is 2 and 5, and the product will be 10.

math tricks for fractions and multiplication - Butterfly Method step 3

Step 4:

Now add the two products. This gives you 19, which the numerator of the sum.

math tricks for fractions and multiplication - Butterfly Method step 4

Step 5:

Getting the denominator is even easier. Just multiply the two denominators, 3 and 5, and that is the denominator of the sum, which is 15.

math tricks for fractions and multiplication - Butterfly Method step 5

Step 6:

So the sum of 2/3 and 3/5 is 19/15.

math tricks for fractions and multiplication - Butterfly Method step 6

Step 7:

Subtracting the fractions is just like adding only, for the numerator, instead of adding the two products you subtract them. L. Glee has made some fantastic mathematical observations in his article that are certainly worth checking out.

math tricks for fractions and multiplication - Butterfly Method step 7 math tricks for fractions and multiplication - Butterfly Method step 7.

 

Multiplying Numbers Close to Hundred

math-tricks-for-fractions-and-multiplication-multiplying-numbers

100 is one of the easiest numbers to multiply with other numbers. However, to multiply with numbers close to 100, for example 97. This is not an easy number to get around and grade 5 students might struggle with the multiplication process. The trick I’m about to show not only makes the task easier, but also saves a lot of time.

Step 1:

So let us take 97 as the number close to hundred and we will multiply it with 5.

math tricks for fractions and multiplication - Multiplication step 1

Step 2:

First we multiply 100 and 5, which will give us 500.

math tricks for fractions and multiplication - Multiplication step 2

Step 3:

Then we multiply 5 and the difference between 97 and 100, which is 3.

 

math tricks for fractions and multiplication - Multiplication step 3 math tricks for fractions and multiplication - Multiplication step 3.

Step 4:

So what you get is (100 x 5) – (5 x 3). This will give you 500 – 15 = 485, which is the required answer.

math tricks for fractions and multiplication - Multiplication step 4

If you want to multiply two numbers close to 100 with each other, the process is a bit different.

Step 1:

Let us take 99 and 98 as the two numbers. First, find the difference of the two numbers from hundred.    This means 100 – 99 = 1 and 100 – 98 = 2.

math tricks for fractions and multiplication - Multiplication close to 100 step 1 math tricks for fractions and multiplication - Multiplication close to 100 step 1.

Step 2:

Now subtract the first number with the second difference or the second number with the first difference. That is, 99 – 2 = 97 and 98 – 1 = 97. As you can see, the result will be the same so you can pick any one you like.

math tricks for fractions and multiplication - Multiplication close to 100 step 2 math tricks for fractions and multiplication - Multiplication close to 100 step 2.

Step 3:

After that, multiply the differences. So, 1 x 2 = 2. If the product is a single digit number, as it is in this case, put a 0 in front of it. So, our desired number will be 1 x 2 = 02. Finally, put 97 and 02 together, and 9702 is your answer.

math tricks for fractions and multiplication - Multiplication close to 100 step 3 math tricks for fractions and multiplication - Multiplication close to 100 step 3.

There you go, folks. These math tricks for fractions and multiplication will no longer give you math fear. In fact, I bet children will be having a lot more fun while learning. If you liked this article and would like to read more, do check out the Logic Roots Blog to find more articles on mathematical tips and tricks.