5th grade

1. Adding and
Subtracting
Decimals

2. Let’s Review !
In 4.35, "4" is the
whole number part,
and ".35" is the
fractional part.
What Are
Decimals?
A decimal is a number that
has a whole number part,
and a fractional part
separated by a decimal point.
4 is the whole
number, 3 is in
the tenth place,
and 5 is in the
hundredths place.
Decimal Place
Value
Each place to the
right of the decimal
point is worth less
than 1.
We use decimals to
express numbers that are
between whole numbers

3. Place Value

4. Each place is ten times the value of the place to its right.

5. Steps for Adding/Subtracting
Decimals
1
Line up decimal points verticaly.
Add a zero placeholder if needed.
Line it up !
2
Beginning in the lowest place
value, begin adding or
subtracting from right to left.
Do the math.
3 Bring down the decimal point.
Bring it down !

6. Adding Decimals Word problem
Sarah went to the store and bought
2 items. The first item cost $6.45,
and the second item cost $3.70.
How much did Sarah spend in total?

7. 6 4
5
3 7
0
1 0 1
5
1
Add
$6.45 + $3.7

8. Subtracting Decimals Word
problem
John had $20. He bought a book
that cost $8.99. How much money
does John have left?

9. Subtract
$20 - $8.99
2 0 0
0
8 9
9
1 1 0
1
10
9
8
1

10. Common Mistakes to Avoid
1.Forgetting to line up decimal points.
2.Not filling in missing zeros: Add extra zeros to help with
alignment (e.g., 5.6 becomes 5.60).
3.Misplacing the decimal point in the answer.

11. Where Do We Use Decimals?
1.You use decimals every day when dealing with:
2.Money (e.g., $5.75)
3.Measurements (e.g., 3.2 cm)
4.Weight (e.g., 1.25 kg)
( Examples: price tags, rulers, or scales. )

12. Exit Ticket
write your own addition or subtraction decimal problem!
Or
write one addition or subtraction decimal problem you found
challenging and how you solved it.
**Write your answer in your math journal.**