Problems based on basic operations

The units metre, gram, and litre are commonly used in daily life to measure length, mass, and capacity, respectively. In commercial transactions, rupees and paise are used as units of currency. Similarly, days, hours, and minutes are standard units for measuring time.

It is essential to understand how fundamental mathematical operations—addition, subtraction, multiplication, and division—are performed using these units of measurement.
1. Add:  37 km 250 m + 15 km 950 m

250 + 950 = 1200
1200 m = 1 km + 200 m
53 km 200 m

2. Subtract: 7 l 150 ml – 2 l 500 ml

We cannot subtract 500 ml from 150 ml. 
Convert 1 l into 1000 ml.
 4 l  650 ml

3. If one dress requires 3 m 25 cm of cloth, how much do 4 dresses need?
Manju’s method:
    3 m  25 cm for the 1st dress     for the 1st dress
+
    3 m  25 cm for the 2nd dress    for the 2nd dress
+
     3 m  25 cm for the 3rd dress    for the 3rd dress
+
    3 m  25 cm for the 4th dress     for the 4th dress
    12 m  100 cm
1 m is 100 cm; therefore, 12 + 1 = 13 m
Kunal's method:
     m        cm
      3          25
×                 4  
     12        100
12 m 100 cm = 13m

4. If a wire that is 9 m 50 cm long is cut into pieces of 5 cm each, how many pieces will be made?
9 m 50 cm = (900 + 50) cm
To find out how many pieces of 5 cm can be made from a wire 950 cm long, let us use division.
    190
`5")"overline(950)`
– 5                   
   45
   45           
   000
       0     
       0
190 pieces will be made.