Examples with solutions for Addition and Subtraction of Decimal Fractions: More than two fractions

Exercise #1

0.85+7.61+2.3= 0.85+7.61+2.3=

Video Solution

Step-by-Step Solution

According to the order of operations, we will solve the exercise from left to right.

We will first calculate the addition exercise in the vertical column, since it contains two numbers after the decimal point:

0.85+7.61=8.46 0.85+7.61=8.46

Now we will get the exercise:

8.46+2.3= 8.46+2.3=

Let's remember that:

2.3=2.30 2.3=2.30

We will calculate in the vertical column and get:

10.76 10.76

Answer

10.76

Exercise #2

8.5+5.2+8.4= ? 8.5+5.2+8.4=\text{ ?}

Video Solution

Step-by-Step Solution

First we will break down each of the factors in the exercise into a whole number and its remainder:

8+0.5+5+0.2+8+0.4= 8+0.5+5+0.2+8+0.4=

Now we'll combine only the whole numbers:

8+5+8=13+8=21 8+5+8=13+8=21

Then we'll calculate the remainder:

0.5+0.2+0.4=0.7+0.4=1.1 0.5+0.2+0.4=0.7+0.4=1.1

Finally, we are left with the following:

21+1.1=22.1 21+1.1=22.1

Answer

22.1

Exercise #3

0.2x+8.6x+0.65x= 0.2x+8.6x+0.65x=

Video Solution

Step-by-Step Solution

According to the order of operations rules, we'll solve the exercise from left to right:

0.2x+8.6x=8.8x 0.2x+8.6x=8.8x

We'll break down 8.8 into a smaller addition exercise that will be easier for us to calculate:

8x+0.8x+0.65x= 8x+0.8x+0.65x=

Now we'll use the commutative property since the exercise only involves addition.

Let's focus on the leftmost addition exercise, remembering that:

0.8=0.80 0.8=0.80

We'll calculate the following exercise:

0.80x+0.65x=1.45x 0.80x+0.65x=1.45x

And finally, we'll get the exercise:

8x+1.45x=9.45x 8x+1.45x=9.45x

Answer

9.45X

Exercise #4

10.1x+5.2x+2.4x= ? 10.1x+5.2x+2.4x=\text{ ?}

Video Solution

Step-by-Step Solution

The first step is factorising each of the terms in the exercise into a whole number and its remainder:

10x+0.1x+5x+0.2x+2x+0.4x= 10x+0.1x+5x+0.2x+2x+0.4x=

Now we'll combine only the whole numbers:

10x+5x+2x=15x+2x=17x 10x+5x+2x=15x+2x=17x

Next, we will calculate the remainder:

0.1x+0.2x+0.4x=0.3x+0.4x=0.7x 0.1x+0.2x+0.4x=0.3x+0.4x=0.7x

Finally, we are left with the following:

17x+0.7x=17.7x 17x+0.7x=17.7x

Answer

17.7x x

Exercise #5

13.4+4.5+0.1= 13.4+4.5+0.1=

Video Solution

Answer

18