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WorksheetsAdd & Subtract Decimals: Estimate, Decompose, and Algorithm
Total questions: 40
Worksheet time: 39mins
Add the parts of decomposed numbers to find _____________
Estimates
Decimals
Partial sums
Decimal grids
To ______________ a number means to break the number into parts by place value or by whole numbers and decimals.
Decimal grid
Estimate
Decompose
Partial sum
A number close to an exact value is called a(n):
Estimate
Decimal
Partial sum
Decompose
5.66 + 4.25 =
10.91
9.91
8.91
9.90
3.3 + 2.22 =
5.52
5.55
5.77
5.4
15.07 - 12.2 =
2.87
1.87
3.87
2.80
6.7 - 2.33 =
4.43
4.4
4.37
4.47
Stephanie has two dogs. Her beagle weighs 16.27 pounds. Her poodle weighs 28.53 pounds. What is the combined weight of both dogs?
448 pounds
44.8 pounds
4.48 pounds
12.26 pounds
Below is the length of three running trails at three parks.
The trail at Lakewood Park is 9.84 miles.
The trail at Kiest Park is 6.7 miles.
The trail at Springfield Park is 13.09 miles.
What is the difference between the length of the trails at Springfield Park and Lakewood Park?
6.75 miles
3.25 miles
29.63 miles
7.65 miles
Alberto had $89.26 in his piggy bank. He purchased a video game that cost $32.79. How much money does Alberto have left in his piggy bank?
$564.70
$122.05
$56.47
$12.25
Which difference is approximately 10?
33.2 – 28.4
70.9 – 58.7
42.5 – 16.8
65.7 – 65.6
Estimate the sum:
69.9 + 22.1 =
(a)
What is the best estimate of 61.4 + 88.3?
100
140
150
200
Estimate the difference:
968.8 - 161
(a)
4.97 + 13.02
Estimate the sum:
22.356 + 49.90 =
72
71
73
What is the rule for adding or subtracting decimals?
Add first.
Line up the decimals first, then fill in with zeros.
Move the decimal to the right the total amount of numbers after the decimal.
Subtract.
Below are the lengths of three running trails at three parks.
The trail at Lakewood Park is 9.84 miles.
The trail at Kiest Park is 6.7 miles.
The trail at Springfield Park is 13.09 miles.
What is the difference between the lengths of the trails at Springfield Park and Lakewood Park?
6.75 miles
3.25 miles
29.63 miles
7.65 miles
Kristen lives 132.95 meters from Dallas, Texas. Brian lives 207.6 meters from Dallas, Texas. What is the difference between these two distances?
340.55 meters
746.5 meters
74.65 meters
7.465 meters
The table shows the number of hours five employees at Frosty Treat Ice-Cream Shop worked in a week. What is the difference between the number of hours Danny and Carmen worked?
208.3 hours
55.35 hours
20.83 hours
21.06 hours
Cynthia measured the length of two plants in her garden. The tomato plant was 23.06 inches long and the bean plant was 9.3 inches long. What is the combined length of both plants?
13.76 inches
10.76 inches
42.46 inches
32.36 inches
Jim earns $22.50, $14.75, and $8.50 on three different days. How much did he earn in total?
(a)
What did the student do incorrectly while solving this equation?
Subtracted instead of added the amounts together
Nothing, the student solved the problem correctly
Did not line up the decimal points
Will the answer to this equation be more or less than 150?
Less than 150
More than 150
Jerry bought 6.95 lbs of cherry and lime jelly beans for his birthday party. If 1.75 lbs were cherry flavored, how many pounds were lime flavored?
5.2
8.7
9.7
5.02
A weatherman was measuring the amount of rain two cities received over a week. City A received 3.74 inches, while City B received 9.8 inches. How much rain did they receive in total?
13.54 inches
6.06 inches
7 days
13.54 rains
Nancy was buying food for her birthday party. She bought a 52.93 oz bag of barbecue chips and a 79.6 oz bag of regular chips. How many ounces did she buy altogether?
132.53 ounces
33.33 ounces
26.77 ounces
60.89 ounces
What do we do when we see a difference?
Add
Subtract
Multiply
Divide
Subtract 0.70-0.08
(a)
Add decimals by decomposing numbers
2.37+3.628
5.678
5.289
5.598
5.998
Solve using decomposition
96.4−12.3
(a)
Solve using partial differences:
3.875−1.471
(a)
What strategy is most efficient for you?
Decomposing
Numbers
Partial
Sums
Algorithm
What is the sum of 7.45 and 3.56?
10.91
11.91
11.01
10.01
Estimate the difference:
45.67 - 23.89 =
22
21
23
24
Lisa has $15.75. She buys a book for $8.99. How much money does she have left?
$7.86
$7.76
$6.76
$6.86
