Page 172 - Math Genius C4

E:\Working\Orange_Education\Math_Genius_4_(08-10-2025)\Open_Files\Chap-09
\\October 8, 2025 5:17 PM Bharat Arora P-9 Reader _________________________ Date: ___________________74

3. Convert the following into m. Solution: (a) m cm mm (b) km m cm
(a) 24 km (b) 96 km (c) 8 km 417 m (d) 26 km 42 m 17 11 9 10 11 9

4. Convert the following into dm. 7 1 15 2 10 0 1 10 15
(a) 39 m (b) 118 m (c) 19 m 9 dm (d) 109 m 2 dm 1 8 2 5 9 3 0 1 2 0 5 0
5. Convert the following into dam. – 9 7 6 4 – 1 6 2 4 5 9 0

(a) 13 km (b) 18 hm (c) 5 km 10 hm 8 4 9 5 1 3 8 7 4 6 0
6. Convert the following into metres. Thus, 18 m 25 cm 9 mm – 9 m Thus, 30 km 120 m 50 cm – 16 km

(a) 2 km 1 hm 6 dam 8 m (b) 12 km 6 hm 9 dam 4 m 76 cm 4 mm = 8 m 49 cm 5 mm. 245 m 90 cm = 13 km 874 m 60 cm.
7. Convert the following. Example 3: Rohan travelled 218 km 352 m by car and 414 km 165 m by bus. Find

(a) 105 mm into cm and mm (b) 685 cm into m and cm the total distance travelled by Rohan.

(c) 8000 m into km (d) 16300 m into km and m Solution: km m

8. Convert the following. 1 1

(a) 18 ft into in (b) 5 ft 24 in into in Distance travelled by car = 2 1 8 3 5 2
Distance travelled by bus = + 4 1 4 1 6 5
(c) 108 in into ft (d) 141 in into ft and in Total distance travelled = 6 3 2 5 1 7

AddiTion And SuBTrAcTion of LengThS Thus, Rohan travelled 632 km 517 m in all.
Example 4: A tree was 21 m 75 cm high. A part measuring 12 m 24 cm from the top
In class 3, we have learned that we arrange the given measures in appropriate broke off due to a storm. How much of the tree is still standing erect?
columns and then add or subtract column-wise. Solution:

Example 1: Add the following: m cm
1 11
(a) 32 m 76 cm 5 mm and 8 m 35 cm 8 mm Height of the tree before breaking = 2 1 7 5
(b) 13 km 975 m 32 cm and 5 km 688 m 55 cm Height of the broken part of the tree = – 1 2 2 4

Solution: (a) (b) Height of the remaining part of the tree = 9 5 1
m cm mm km m cm
Thus, 9 m 51 cm of the tree is still standing erect.
1 1 1 1 1 1 1

3 2 7 6 5 1 3 9 7 5 3 2 Think Tank Critical Thinking
+ 8 3 5 8 + 5 6 8 8 5 5 What is the difference between the distances of your school and your father's
4 1 1 2 3 1 9 6 6 3 8 7 office from home?

Thus, 32 m 76 cm 5 mm + 8 m Thus, 13 km 975 m 32 cm + 5 km Practice Time 9B

35 cm 8 mm = 41 m 12 cm 3 mm. 688 m 55 cm = 19 km 663 m 87 cm.
Example 2: Subtract the following: 1. Add the following: (b) (c)
(a)
cm
cm
m
m
cm mm
km
km
m
(a) 9 m 76 cm 4 mm from 18 m 25 cm 9 mm 2 4 1 7 5 4 2 2 1 3 3 8 mm 1 8 2 1 8 4 3 2
6
(b) 16 km 245 m 90 cm from 30 km 120 m 50 m 1 3 1 0 4 5 3 1 4 1 4 3 5 2 4 1 4 8 3 7 5
Teacher’s Encourage students to keep the process of carrying or borrowing in mind. It will help them in doing calculation + 0 5 0 8 1 0 9 + 1 2 0 9 1 7 + 3 4 2 3 3 7 2 2
Tip fast.
170 Mathematics-4