Scroll:Operations with decimals >> Estimate sums, differences and products of decimals >> saq (3926)

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

10.2 + 3.12

The sum is approximately :


Answer:_______________




2)  

 Estimate the product. Round each factor to the nearest whole number, and then multiply.

2.9 x 1.2

The product is approximately :


Answer:_______________




3)  

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

9.3 - 3.3

The difference is approximately :


Answer:_______________




4)  

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

8.1 + 3.14

The sum is approximately :


Answer:_______________




5)  

 Estimate the product. Round each factor to the nearest whole number, and then multiply.

1.8 x 2.1

The product is approximately :


Answer:_______________




6)  

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

10.2 - 3.2

The difference is approximately :


Answer:_______________




7)  

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

7.2 + 1.21

The sum is approximately :


Answer:_______________




8)  

 Estimate the product. Round each factor to the nearest whole number, and then multiply.

2.8 x 4.2

The product is approximately :


Answer:_______________




9)  

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

6.3 - 1.2

The difference is approximately :


Answer:_______________




10)  

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

6.2 + 3.17

The sum is approximately :


Answer:_______________




 

1)  

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

10.2 + 3.12

The sum is approximately : Answer: 13


SOLUTION 1 :

Round each number to the nearest whole number.

10.2 + 3.12  =

10 + 3  =

Now subtract:

10 + 3  = 13

The sum is about 13.

Compare your estimate to the exact answer:

10.2 + 3.12  = 13.32 → ans = 13

 



2)  

 Estimate the product. Round each factor to the nearest whole number, and then multiply.

2.9 x 1.2

The product is approximately : Answer: 3


SOLUTION 1 :

Round each decimal to the nearest whole number.

2.9 × 1.2  = 3.48   →     (ans) = 3
 



3)  

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

9.3 - 3.3

The difference is approximately : Answer: 6


SOLUTION 1 :

Round each number to the nearest whole number.

9.3 – 3.3  =

9 – 3  =

Now subtract:

9 – 3  = 6

The difference is about 6.

Compare your estimate to the exact answer:

9.3 – 3.3  = 6 → 6

 



4)  

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

8.1 + 3.14

The sum is approximately : Answer: 11


SOLUTION 1 :

Round each number to the nearest whole number.

8.1 + 3.14  =

8 + 3  =

Now subtract:

8 + 3  = 11

The sum is about 11.

Compare your estimate to the exact answer:

8.1 + 3.14  = 11.24 → ans = 11

 



5)  

 Estimate the product. Round each factor to the nearest whole number, and then multiply.

1.8 x 2.1

The product is approximately : Answer: 4


SOLUTION 1 :

Round each decimal to the nearest whole number.

1.8 × 2.1  = 3.78   →     (ans) = 4
 



6)  

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

10.2 - 3.2

The difference is approximately : Answer: 7


SOLUTION 1 :

Round each number to the nearest whole number.

10.2 – 3.2  =

10 – 3  =

Now subtract:

10 – 3  = 7

The difference is about 7.

Compare your estimate to the exact answer:

10.2 – 3.2  = 7 → 7

 



7)  

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

7.2 + 1.21

The sum is approximately : Answer: 8


SOLUTION 1 :

Round each number to the nearest whole number.

7.2 + 1.21  =

7 + 1  =

Now subtract:

7 + 1  = 8

The sum is about 8.

Compare your estimate to the exact answer:

7.2 + 1.21  = 8.41 → ans = 8

 



8)  

 Estimate the product. Round each factor to the nearest whole number, and then multiply.

2.8 x 4.2

The product is approximately : Answer: 12


SOLUTION 1 :

Round each decimal to the nearest whole number.

2.8 × 4.2  = 11.76   →     (ans) = 12
 



9)  

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

6.3 - 1.2

The difference is approximately : Answer: 5


SOLUTION 1 :

Round each number to the nearest whole number.

6.3 – 1.2  =

6 – 1  =

Now subtract:

6 – 1  = 5

The difference is about 5.

Compare your estimate to the exact answer:

6.3 – 1.2  = 5.1 → 5

 



10)  

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

6.2 + 3.17

The sum is approximately : Answer: 9


SOLUTION 1 :

Round each number to the nearest whole number.

6.2 + 3.17  =

6 + 3  =

Now subtract:

6 + 3  = 9

The sum is about 9.

Compare your estimate to the exact answer:

6.2 + 3.17  = 9.37 → ans = 9