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.

145.19 + 348.17

The sum is approximately



 


Answer:_______________




2)  

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

5.24 - 1.70

The difference is approximately



 


Answer:_______________




3)  

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

37.21 + 42.14

The sum is approximately



 


Answer:_______________




4)  

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

6.36 + 4.73

The sum is approximately



 


Answer:_______________




5)  

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

6.18 + 6.21

The sum is approximately



 


Answer:_______________




6)  

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

30.35 - 12.88

The difference is approximately



 


Answer:_______________




7)  

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

912.18 + 939.11

The sum is approximately



 


Answer:_______________




8)  

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

8.24 - 1.75

The difference is approximately



 


Answer:_______________




9)  

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

20.20 + 52.20

The sum is approximately



 


Answer:_______________




10)  

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

2.22 + 9.74

The sum is approximately



 


Answer:_______________




 

1)  

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

145.19 + 348.17

The sum is approximately Answer: 493



 


SOLUTION 1 :

Round each number to the nearest whole number.

145.19 + 348.17  =

145 + 348  =


Now add:

145 + 348  = 493


The sum is about 493.

Compare your estimate to the exact answer:

145.19 + 348.17  = 493.36



2)  

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

5.24 - 1.70

The difference is approximately Answer: 3



 


SOLUTION 1 :

Round each number to the nearest whole number.

5.24 - 1.70  =

5 - 2  =


Now Subtract:

5 - 2  = 3


The sum is about 3.

Compare your estimate to the exact answer:

5.24 - 1.70  = 3.54



3)  

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

37.21 + 42.14

The sum is approximately Answer: 79



 


SOLUTION 1 :

Round each number to the nearest whole number.

37.21 + 42.14  =

37 + 42  =


Now add:

37 + 42  = 79


The sum is about 79.

Compare your estimate to the exact answer:

37.21 + 42.14  = 79.35



4)  

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

6.36 + 4.73

The sum is approximately Answer: 11



 


SOLUTION 1 :

Round each number to the nearest whole number.

6.36 + 4.73  =

6 + 5  =


Now add:

6 + 5  = 11


The sum is about 11.

Compare your estimate to the exact answer:

6.36 + 4.73  = 11.09



5)  

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

6.18 + 6.21

The sum is approximately Answer: 12



 


SOLUTION 1 :

Round each number to the nearest whole number.

6.18 + 6.21  =

6 + 6  =


Now add:

6 + 6  = 12


The sum is about 12.

Compare your estimate to the exact answer:

6.18 + 6.21  = 12.39



6)  

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

30.35 - 12.88

The difference is approximately Answer: 17



 


SOLUTION 1 :

Round each number to the nearest whole number.

30.35 - 12.88  =

30 - 13  =


Now Subtract:

30 - 13  = 17


The sum is about 17.

Compare your estimate to the exact answer:

30.35 - 12.88  = 17.47



7)  

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

912.18 + 939.11

The sum is approximately Answer: 1851



 


SOLUTION 1 :

Round each number to the nearest whole number.

912.18 + 939.11  =

912 + 939  =


Now add:

912 + 939  = 1851


The sum is about 1851.

Compare your estimate to the exact answer:

912.18 + 939.11  = 1851.29



8)  

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

8.24 - 1.75

The difference is approximately Answer: 6



 


SOLUTION 1 :

Round each number to the nearest whole number.

8.24 - 1.75  =

8 - 2  =


Now Subtract:

8 - 2  = 6


The sum is about 6.

Compare your estimate to the exact answer:

8.24 - 1.75  = 6.49



9)  

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

20.20 + 52.20

The sum is approximately Answer: 72



 


SOLUTION 1 :

Round each number to the nearest whole number.

20.20 + 52.20  =

20 + 52  =


Now add:

20 + 52  = 72


The sum is about 72.

Compare your estimate to the exact answer:

20.20 + 52.20  = 72.4



10)  

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

2.22 + 9.74

The sum is approximately Answer: 12



 


SOLUTION 1 :

Round each number to the nearest whole number.

2.22 + 9.74  =

2 + 10  =


Now add:

2 + 10  = 12


The sum is about 12.

Compare your estimate to the exact answer:

2.22 + 9.74  = 11.96