Grade 5 - Mathematics 6.18 Adding and Subtracting with Different Units
Mathematical operations are carried out in the same way as normal decimal number operations. Note, that the quantities involved in the calculations are all expressed in the same units.
Examples:
19 cm + 23 m + 25.9 m
First convert everything to the same units:
19 cm = 0.19 meters
0.19 m + 23 m + 25.9 m = 49.09 m
Another way is to convert everything to centimeters and perform addition operation
23 m = 1300 cm
25.9 m = 1590 cm
19 cm + 2 300 cm + 2 590 cm = 4 909 cm
Final answer is expressed in meters as: 49.09 m
A rope is 3 metres long. You cut 100 cms out of it. How many metres of the rope are remaining?
1 metre = 100 cms
Hence 3 m - 1m = 2m Answer: 2 m
Directions: Answer the following questions. Also write at least ten examples of your own.