How to add and subtract decimals - HSPT Math
Card 0 of 108
What is 16.7548 rounded to the nearest tenth?
What is 16.7548 rounded to the nearest tenth?
The tenth's place is the position one unit to the right of the decimal point. In this case, that is the 7.
After identifying the position, we need to determine if this number remains 7 or if we need to round it up to 8. If the number to the right of the tenth's place is 4 or lower, then our number will remain 7. If it is 5 or greater, then we will round the 7 up to 8.
In this case, the number is indeed 5, so our tenth's place becomes 8. All numbers to the left of the tenth's place will remain the same.
The tenth's place is the position one unit to the right of the decimal point. In this case, that is the 7.
After identifying the position, we need to determine if this number remains 7 or if we need to round it up to 8. If the number to the right of the tenth's place is 4 or lower, then our number will remain 7. If it is 5 or greater, then we will round the 7 up to 8.
In this case, the number is indeed 5, so our tenth's place becomes 8. All numbers to the left of the tenth's place will remain the same.
Compare your answer with the correct one above
To subtract decimals you place the first decimal over the top of the other aligned by the decimal point. If there are no numbers after a tens, hundredths, or thousandths place or further to the right of the decimal just add a zero in the required areas.
For example
becomes 
Then go through each place and subtract the top number by the bottom number. Subtract the numbers in each place like you would any number.
The example we are working with will look like this 
The answer after subtraction is 
To subtract decimals you place the first decimal over the top of the other aligned by the decimal point. If there are no numbers after a tens, hundredths, or thousandths place or further to the right of the decimal just add a zero in the required areas.
For example becomes
Then go through each place and subtract the top number by the bottom number. Subtract the numbers in each place like you would any number.
The example we are working with will look like this
The answer after subtraction is
Compare your answer with the correct one above
Subtract: 
Subtract:
Rewrite the decimal as a fraction and subtract:

Reduce this:

Rewrite the decimal as a fraction and subtract:
Reduce this:
Compare your answer with the correct one above
Evaluate: 
Evaluate:
Add the first two numbers, making sure you align the decimal points in the addends and the sum:

Now subtract the third number, making sure you again align the decimal points:

Add the first two numbers, making sure you align the decimal points in the addends and the sum:
Now subtract the third number, making sure you again align the decimal points:
Compare your answer with the correct one above
Combine:

Combine:
First, combine the positive decimals, which gives you
.
Then, you can subtract that from
, but remember that your answer is negative since it's a
.
Your answer is
.
First, combine the positive decimals, which gives you .
Then, you can subtract that from , but remember that your answer is negative since it's a
.
Your answer is .
Compare your answer with the correct one above
Write the value of this expression as a decimal:

Write the value of this expression as a decimal:
Simplify the sum by taking the least common denominator, which is 12:



Divide 13 by 12:

Simplify the sum by taking the least common denominator, which is 12:
Divide 13 by 12:
Compare your answer with the correct one above
Which of the following is the sum of nine tenths and nineteen thousandths?
Which of the following is the sum of nine tenths and nineteen thousandths?
Nine tenths is equal to 0.9; nineteen thousandths is equal to 0.019. Add them, rewriting 0.9 as 0.900:



Nine tenths is equal to 0.9; nineteen thousandths is equal to 0.019. Add them, rewriting 0.9 as 0.900:
Compare your answer with the correct one above
Simplify the following:

Simplify the following:
To add decimals, first add zeros to the necessary terms so they all have the same number of places to the right of the decimal point.

Now, temporarily drop the decimal and add the numbers as if they were whole numbers.

Finally, add the decimal place back in, in the same place you removed it from. In this case, we originally modified our numbers so they all had 3 numbers to the right of the decimal, so we will add the decimal back to the exact same place. Thus, our answer is:

To add decimals, first add zeros to the necessary terms so they all have the same number of places to the right of the decimal point.
Now, temporarily drop the decimal and add the numbers as if they were whole numbers.
Finally, add the decimal place back in, in the same place you removed it from. In this case, we originally modified our numbers so they all had 3 numbers to the right of the decimal, so we will add the decimal back to the exact same place. Thus, our answer is:
Compare your answer with the correct one above
Add: 
Add:
Rewrite the problem so that the tenths, hundredths, and thousandths digits align. Use zeros as placeholders and solve.

Rewrite the problem so that the tenths, hundredths, and thousandths digits align. Use zeros as placeholders and solve.
Compare your answer with the correct one above
Add: 
Add:
Ensure that each digit is added to the correct digit.
Add three zeros at the end of
as placeholders.

Add the tenths place with the tenths place (in this case
), hundredth place with the hundredth place (in this case
) , thousandth place with thousandth place (in this case
), and ten thousandth place with ten thousandth place (in this acase
)

Ensure that each digit is added to the correct digit.
Add three zeros at the end of as placeholders.
Add the tenths place with the tenths place (in this case ), hundredth place with the hundredth place (in this case
) , thousandth place with thousandth place (in this case
), and ten thousandth place with ten thousandth place (in this acase
)
Compare your answer with the correct one above
Add 
Add
Add the placeholder for the hundredths place after
.
Rewrite the problem:

Add the hundredths place.

Add the tenths place.

Combine the numbers.

The decimal place is two places from the right.
The correct answer is: 
Add the placeholder for the hundredths place after .
Rewrite the problem:
Add the hundredths place.
Add the tenths place.
Combine the numbers.
The decimal place is two places from the right.
The correct answer is:
Compare your answer with the correct one above
Add the decimals: 
Add the decimals:
Be careful not to misalign and add the wrong digits. Add placeholders to the end of the decimals so that we can see the tenths and hundreds places.

Add the numbers in the hundredth place.

Add the numbers in the tenths place.

Add the ones digits.

Combine the numbers.
The answer is: 
Be careful not to misalign and add the wrong digits. Add placeholders to the end of the decimals so that we can see the tenths and hundreds places.
Add the numbers in the hundredth place.
Add the numbers in the tenths place.
Add the ones digits.
Combine the numbers.
The answer is:
Compare your answer with the correct one above
There is a regular sliced pizza (8 slices) that only has 6 slices left. If someone ate 4 more, what are the remaining slices in a decimal form?
There is a regular sliced pizza (8 slices) that only has 6 slices left. If someone ate 4 more, what are the remaining slices in a decimal form?
The starting amount of slices is
out of
which is
or
of the whole pizza.
The
other slices that someone ate is half the whole pie or
.
So to find the remaining amount you must subtract
from
which gives you a quarter or
.
The starting amount of slices is out of
which is
or
of the whole pizza.
The other slices that someone ate is half the whole pie or
.
So to find the remaining amount you must subtract from
which gives you a quarter or
.
Compare your answer with the correct one above
Define an operation
on the set of real numbers as follows:

If
, then evaluate
.
Define an operation on the set of real numbers as follows:
If , then evaluate
.
,
so
.
If
, then



,
so
.
If
, then
Compare your answer with the correct one above
First you want to add up your hundredths places to get
.
Then you do the same for the tenths places to get
.
Finally, put them together to get
.
First you want to add up your hundredths places to get
.
Then you do the same for the tenths places to get
.
Finally, put them together to get .
Compare your answer with the correct one above
What is 16.7548 rounded to the nearest tenth?
What is 16.7548 rounded to the nearest tenth?
The tenth's place is the position one unit to the right of the decimal point. In this case, that is the 7.
After identifying the position, we need to determine if this number remains 7 or if we need to round it up to 8. If the number to the right of the tenth's place is 4 or lower, then our number will remain 7. If it is 5 or greater, then we will round the 7 up to 8.
In this case, the number is indeed 5, so our tenth's place becomes 8. All numbers to the left of the tenth's place will remain the same.
The tenth's place is the position one unit to the right of the decimal point. In this case, that is the 7.
After identifying the position, we need to determine if this number remains 7 or if we need to round it up to 8. If the number to the right of the tenth's place is 4 or lower, then our number will remain 7. If it is 5 or greater, then we will round the 7 up to 8.
In this case, the number is indeed 5, so our tenth's place becomes 8. All numbers to the left of the tenth's place will remain the same.
Compare your answer with the correct one above
What is 16.7548 rounded to the nearest tenth?
What is 16.7548 rounded to the nearest tenth?
The tenth's place is the position one unit to the right of the decimal point. In this case, that is the 7.
After identifying the position, we need to determine if this number remains 7 or if we need to round it up to 8. If the number to the right of the tenth's place is 4 or lower, then our number will remain 7. If it is 5 or greater, then we will round the 7 up to 8.
In this case, the number is indeed 5, so our tenth's place becomes 8. All numbers to the left of the tenth's place will remain the same.
The tenth's place is the position one unit to the right of the decimal point. In this case, that is the 7.
After identifying the position, we need to determine if this number remains 7 or if we need to round it up to 8. If the number to the right of the tenth's place is 4 or lower, then our number will remain 7. If it is 5 or greater, then we will round the 7 up to 8.
In this case, the number is indeed 5, so our tenth's place becomes 8. All numbers to the left of the tenth's place will remain the same.
Compare your answer with the correct one above
To subtract decimals you place the first decimal over the top of the other aligned by the decimal point. If there are no numbers after a tens, hundredths, or thousandths place or further to the right of the decimal just add a zero in the required areas.
For example
becomes 
Then go through each place and subtract the top number by the bottom number. Subtract the numbers in each place like you would any number.
The example we are working with will look like this 
The answer after subtraction is 
To subtract decimals you place the first decimal over the top of the other aligned by the decimal point. If there are no numbers after a tens, hundredths, or thousandths place or further to the right of the decimal just add a zero in the required areas.
For example becomes
Then go through each place and subtract the top number by the bottom number. Subtract the numbers in each place like you would any number.
The example we are working with will look like this
The answer after subtraction is
Compare your answer with the correct one above
Subtract: 
Subtract:
Rewrite the decimal as a fraction and subtract:

Reduce this:

Rewrite the decimal as a fraction and subtract:
Reduce this:
Compare your answer with the correct one above
Evaluate: 
Evaluate:
Add the first two numbers, making sure you align the decimal points in the addends and the sum:

Now subtract the third number, making sure you again align the decimal points:

Add the first two numbers, making sure you align the decimal points in the addends and the sum:
Now subtract the third number, making sure you again align the decimal points:
Compare your answer with the correct one above