Examples with solutions for Multiplication of Decimal Fractions: More than two fractions

Exercise #1

4.5×3.2×5.6= 4.5\times3.2\times5.6=

Video Solution

Step-by-Step Solution

According to the order of operations rules, we will solve the exercise from left to right since multiplication is the only operation in it.

We will solve the left exercise vertically to avoid confusion and get:

4.5×3.2=14.40 4.5\\\times3.2\\=14.40

It is important to maintain correct positioning of the exercise, with the decimal point serving as an anchor.
Then we can multiply in order, first the ones digit of the first number by the ones digit of the second number,
then the tens digit of the first number by the ones digit of the second number, and so on.

Now we will get the exercise:

14.40×5.6= 14.40\times5.6=

Let's remember that:

14.40=14.4 14.40=14.4

We will solve the exercise vertically as well, and remember the rules of keeping the decimal point and multiplying in order (ones, tens, and so on)

And we will get:

14.4×5.6=80.64 14.4\\\times5.6\\=80.64

Answer

80.64 80.64

Exercise #2

11.2×5.6×7.3= 11.2\times5.6\times7.3=

Video Solution

Step-by-Step Solution

According to the order of operations rules, we will solve the exercise from left to right since multiplication is the only operation in it.

We will solve the left exercise vertically to avoid confusion and get:

11.2×5.6=62.72 11.2\\\times5.6\\=62.72

It's important to maintain correct positioning of the exercise, with the decimal point serving as an anchor.
Then we can multiply in order, first the ones digit of the first number by the ones digit of the second number,
then the tens digit of the first number by the ones digit of the second number, and so on.

Now we'll get the exercise:

62.72×7.3= 62.72\times7.3=

Let's remember that:

7.3=7.30 7.3=7.30

We will solve the exercise vertically as well, remembering the rules about keeping the decimal point aligned and multiplying in order (ones, tens, and so on)

And we'll get:

457.856 457.856

Answer

457.856 457.856

Exercise #3

0.5×6.7×6.31= 0.5\times6.7\times6.31=

Video Solution

Step-by-Step Solution

According to the order of operations rules, we will solve the exercise from left to right since multiplication is the only operation in it.

We will solve the left exercise vertically to avoid confusion and get:

0.5×6.7=3.35 0.5\\\times6.7\\=3.35

It is important to maintain correct positioning of the exercise, with the decimal point serving as an anchor.
Then we can multiply in order, first the ones digit of the first number by the ones digit of the second number,
then the tens digit of the first number by the ones digit of the second number, and so on.

Now we will get the exercise:

3.35×6.31= 3.35\times6.31=

We will solve the exercise vertically as well, remembering the rules of keeping the decimal point and multiplying in order (ones, tens, and so on)

And we will get:

3.35×6.31=21.1385 3.35\\\times6.31\\=21.1385

Answer

21.1385 21.1385

Exercise #4

15.6×5.2x×0.3= 15.6\times5.2x\times0.3=

Video Solution

Step-by-Step Solution

Let's look at the exercise, and we'll see that we have two "regular" numbers and one number with a variable.
Since this is a multiplication exercise, there's no problem multiplying a number with a variable by a number without a variable.

In fact, it's important to remember that a variable attached to a number represents multiplication by itself, for example in this case: 5.2×x 5.2\times x
Therefore, we can use the distributive property to separate the variable, and come back to it later.
We'll solve the exercise from left to right.

We'll solve the left exercise vertically to avoid confusion and get:

     15.6×    5.2= 81.12 ~~~~~15.6 \\\times~~~~5.2 \\=~81.12

It's important to be careful with the correct placement of the exercise, where the decimal point serves as an anchor.
Then we can multiply in order, first the ones digit of the first number by the ones digit of the second number,
then the tens digit of the first number by the ones digit of the second number, and so on.

Now we'll get the exercise:

81.21×0.3= 81.21\times0.3=

Let's remember that:

0.3=0.30 0.3=\text{0}.30

And we'll get:

24.336 24.336

Let's not forget to add the variable at the end, and thus the answer will be:

24.336x 24.336 x

Answer

24.336x 24.336x