Important Questions for Class 6 Maths - Decimals

Q1: Subtract the sum of 114.753 and 70.14 from the sum of 93.12 and 212.15.
Ans:


Q2: Express the following as cm using decimals 116 mm.
Ans:


Q3: Express the following as cm using decimals: 30 mm
Ans: So 30mm = 30/10cm = 3cm = 3.0cm.

Q4: Arrange the following decimal numbers in descending order.
8.51, 8.06, 9.10, 8.57
Ans: The given decimal numbers are like decimals. By checking the digits before decimal, we observe that 9.10 is largest of given numbers. Among the remaining numbers, by checking the tenths place, we observe that 8.06 is the least. Out of remaining numbers, by checking the hundredths place, we observe that 8.57 is bigger than 8.51. So, by arranging the given numbers from big to small, we have,
⇒ 9.10, 8.57, 8.51, 8.06

Q5: Fill in the blanks.

Ans: (a) 10, 100, 1000.
In the decimal number, 25.135, 1 is in tenths place. So its place value is 1/10, 3 is in hundredths place. So, its place value is 3/100.
6 is in thousandths place. So, its place value is 6/1000.

(b) 6, 10, 1000
In the decimal number, 66..606, the place values of each 6 from left to right are: 60, 6, 6/10, 0/100,6/1000
Therefore, 66.606 = 60 + 6 + 6/10 + 0 + 6/1000.
(c) 6, 5
The given expanded form 14 + 5/1000 + 6/10 can be written in the correct order as, 14 + 6/10 + 0/100 + 5/1000 i.e., 6 is in tenths place, 0 is in hundredths place and 5 is in thousandths place.
So, the decimal number can be written as 14.605.
(d) 5, 4
The given expanded form 4100+5 can be written in the correct order as, 5 + 0/10 + 4/100.
i.e., 0 is in tenths place and 4 is in hundredths place. So, the decimal number can be written as 5.04.

Q6: 1.24 + 7.23 = _______
Ans: 1.24 + 7.23 = 8.47

Q7: Find: 0.29 + 0.36
Ans: 0.29 + 0.36 = 0.65

Q8: Write the decimal number represented by the points S on the given number line.
Ans: S is lies after 1 and fifth part toward right. So the decimal number represented by the points S on the given number line is 1.5.

Q9: Subtract 0.314 kg from 2.107 kg.
Ans: 0.314 kg from 2.107 kg = 1.793 kg


Q10: Show 1.1 on the number line.
Ans: We know that 1.1 is more than one but less than two. There is one-tenth in it. Divide the unit length between 1 and 2 into 10 equal parts and take 1 part as shown below:

Q11: Express 6/100 as decimal.
Ans: 6/100 = 0.06
1mm = 1/10 cm.

Q12: State True or False:
(a) Rs. 60.75 can also expressed as 60Rs 75p.
(b) Adding 70.25 and 14.6 gives 84.85.
(c) 1 kg is equals to 100 grams.
(d) Expanded form of 23.05 is 20 + 3 + 0/10 + 5/100
Ans: (a) True(Rs.60.75 = Rs 60 + Rs 0.75 = Rs 60 + Rs 75/100 = 60Rs 75p)
(b) True ( By changing both numbers in to like decimals and adding, 70.25 + 14.60 = 84.85)
(c) False (We know that 1Kg = 1000g)
(d) True ( The expanded form of 23.05 = 2 Tens + 3 Ones + 0 Tenths + 5 Hundredths = 20 + 3 + 0/10 + 5/100).

Q13: Match the following:
Ans: (a) → iii
100 cm = 1 m
so, 5 cm = 5/100 m
Therefore, 2 m 5 cm = 2 m + 5/100 m
= 2 m + 0.05 m
= 2.05 m
(b) → iv
1 km = 1000 m
14.035 km = 14.035 × 1000 m
= 14035 m
= 14000 m + 35 m
= 14 km + 35 m = 14 km 35 m.
(c) → i
1 Rupee = 100 paise
Rs. 20.15 = 20.15 × 100 p
= 2015 paise
= 2000 paise + 15 paise
= 20 Rupees + 15 paise = 20 Rupees 15 paise.
(d) → ii
100 paise = 1 Rupee
50 paise = Rs. 50/100 = Rs. 0.50.

Q14: 31.24 + 7.03 = _______
Ans: 31.24 + 7.03 = 38.27

Q15: 3 g = ________ kg
Ans: 1000 g = 1 kg3 g = 3/1000 kg = 0.003 kg.