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Question 831399: please help me solve this sum: add 19m55cm,25m 45cm and 79 cm.
Answer by KMST(5328)   (Show Source):
You can put this solution on YOUR website! The metric system of units makes subunits easy.
 cm (centimeter) is  of a meter (0.01m), so
55 cm = 0.55 m, 45 cm = 0.45 m, and 79 cm = 0.79 m.
So 19 meters and 55 centimeters (19m55cm) is 19.55 meters, and
25 meters and 45 centimeters (25m45cm) is 25.45 meters.
We can add all the quantities in meters to get an answer in meters.
19.55 + 25.45 + 0.79 = 45.79
They add up to 45.79 meters, so the answer is  .
Do not forget to show the units in the answer, and if the teacher wanted it expressed that way, the answer can be given as 45m79cm.
NOTES:
1) This could be a mental math problem.
Since 45+55=100, when adding in our head, we know that the 0.45+0.55=1.00 decimal parts of the first 2 numbers add to 1.00 (one whole meter).
That tells us that the first 2 numbers (18.55+25.45) add up to
19+1+25=(19+1)+25=20+25=45.
That's easy to do without pencil and paper or calculator.
2) Some teacher could insist in seeing units shown throughout the problem, and would require that you write the sum as
19.55m + 25.45m + 0.79m = 45.79m
Then, adding 79cm (0.79m) to 45.00m, we get 45.79m.
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