Scroll:Add and subtract decimals >> Estimate sums and differences of decimals >> saq (3662)

Written Instructions:

For each Multiple Choice Question (MCQ), four options are given. One of them is the correct answer. Make your choice (1,2,3 or 4). Write your answers in the brackets provided..

For each Short Answer Question(SAQ) and Long Answer Question(LAQ), write your answers in the blanks provided.

Leave your answers in the simplest form or correct to two decimal places.


 

1)  

 Estimate the sum by rounding each number to the nearest whole number and then adding.

75.19 + 83.12

The sum is approximately



 


Answer:_______________




2)  

 Estimate the difference by rounding each number to the nearest whole number and then subtracting.

8.19 - 1.67

The difference is approximately



 


Answer:_______________




3)  

 Estimate the sum by rounding each number to the nearest whole number and then adding.

6.31 + 9.79

The sum is approximately



 


Answer:_______________




4)  

 Estimate the sum by rounding each number to the nearest whole number and then adding.

1.14 + 9.17

The sum is approximately



 


Answer:_______________




5)  

 Estimate the sum by rounding each number to the nearest whole number and then adding.

847.18 + 587.18

The sum is approximately



 


Answer:_______________




6)  

 Estimate the difference by rounding each number to the nearest whole number and then subtracting.

38.36 - 12.70

The difference is approximately



 


Answer:_______________




7)  

 Estimate the sum by rounding each number to the nearest whole number and then adding.

34.15 + 70.12

The sum is approximately



 


Answer:_______________




8)  

 Estimate the difference by rounding each number to the nearest whole number and then subtracting.

5.42 - 3.78

The difference is approximately



 


Answer:_______________




9)  

 Estimate the sum by rounding each number to the nearest whole number and then adding.

8.15 + 1.76

The sum is approximately



 


Answer:_______________




10)  

 Estimate the sum by rounding each number to the nearest whole number and then adding.

1.16 + 1.13

The sum is approximately



 


Answer:_______________




 

1)  

 Estimate the sum by rounding each number to the nearest whole number and then adding.

75.19 + 83.12

The sum is approximately Answer: 158



 


SOLUTION 1 :

Round each number to the nearest whole number.

75.19 + 83.12  =

75 + 83  =


Now add:

75 + 83  = 158


The sum is about 158.

Compare your estimate to the exact answer:

75.19 + 83.12  = 158.31



2)  

 Estimate the difference by rounding each number to the nearest whole number and then subtracting.

8.19 - 1.67

The difference is approximately Answer: 6



 


SOLUTION 1 :

Round each number to the nearest whole number.

8.19 - 1.67  =

8 - 2  =


Now Subtract:

8 - 2  = 6


The sum is about 6.

Compare your estimate to the exact answer:

8.19 - 1.67  = 6.52



3)  

 Estimate the sum by rounding each number to the nearest whole number and then adding.

6.31 + 9.79

The sum is approximately Answer: 16



 


SOLUTION 1 :

Round each number to the nearest whole number.

6.31 + 9.79  =

6 + 10  =


Now add:

6 + 10  = 16


The sum is about 16.

Compare your estimate to the exact answer:

6.31 + 9.79  = 16.1



4)  

 Estimate the sum by rounding each number to the nearest whole number and then adding.

1.14 + 9.17

The sum is approximately Answer: 10



 


SOLUTION 1 :

Round each number to the nearest whole number.

1.14 + 9.17  =

1 + 9  =


Now add:

1 + 9  = 10


The sum is about 10.

Compare your estimate to the exact answer:

1.14 + 9.17  = 10.31



5)  

 Estimate the sum by rounding each number to the nearest whole number and then adding.

847.18 + 587.18

The sum is approximately Answer: 1434



 


SOLUTION 1 :

Round each number to the nearest whole number.

847.18 + 587.18  =

847 + 587  =


Now add:

847 + 587  = 1434


The sum is about 1434.

Compare your estimate to the exact answer:

847.18 + 587.18  = 1434.36



6)  

 Estimate the difference by rounding each number to the nearest whole number and then subtracting.

38.36 - 12.70

The difference is approximately Answer: 25



 


SOLUTION 1 :

Round each number to the nearest whole number.

38.36 - 12.70  =

38 - 13  =


Now Subtract:

38 - 13  = 25


The sum is about 25.

Compare your estimate to the exact answer:

38.36 - 12.70  = 25.66



7)  

 Estimate the sum by rounding each number to the nearest whole number and then adding.

34.15 + 70.12

The sum is approximately Answer: 104



 


SOLUTION 1 :

Round each number to the nearest whole number.

34.15 + 70.12  =

34 + 70  =


Now add:

34 + 70  = 104


The sum is about 104.

Compare your estimate to the exact answer:

34.15 + 70.12  = 104.27



8)  

 Estimate the difference by rounding each number to the nearest whole number and then subtracting.

5.42 - 3.78

The difference is approximately Answer: 1



 


SOLUTION 1 :

Round each number to the nearest whole number.

5.42 - 3.78  =

5 - 4  =


Now Subtract:

5 - 4  = 1


The sum is about 1.

Compare your estimate to the exact answer:

5.42 - 3.78  = 1.64



9)  

 Estimate the sum by rounding each number to the nearest whole number and then adding.

8.15 + 1.76

The sum is approximately Answer: 10



 


SOLUTION 1 :

Round each number to the nearest whole number.

8.15 + 1.76  =

8 + 2  =


Now add:

8 + 2  = 10


The sum is about 10.

Compare your estimate to the exact answer:

8.15 + 1.76  = 9.91



10)  

 Estimate the sum by rounding each number to the nearest whole number and then adding.

1.16 + 1.13

The sum is approximately Answer: 2



 


SOLUTION 1 :

Round each number to the nearest whole number.

1.16 + 1.13  =

1 + 1  =


Now add:

1 + 1  = 2


The sum is about 2.

Compare your estimate to the exact answer:

1.16 + 1.13  = 2.29