In a decimal number 12.43, 12 is the whole number part and 43 is the decimal part.
Anurag solved three addition problems on decimal numbers as shown below. The method followed is also written below.
Problem I: 12.43 + 2.34 = (12+2). (43+34) = 14.77
Method followed: He added whole number parts separately and decimal parts separately as shown above and put the decimal in between resultant whole number part and decimal part.
Now, he followed the same method (followed in the problem I) for problem II and problem III as shown below.
Problem II: 1.12+2.5 = (1+2). (12+5) = 3.17
Problem III: 2.56 + 1.62 = (2+1). (56+62) = 3.118
The teacher said that the answers for the Problem II and problem III are wrong.
Now, answer the following questions. (Hint: use place value)
(a) Why did the above method fail for Problem II, but gave the correct answer for Problem I. Explain the reasoning behind it?
(b) Why did the above method fail for Problem III?
Make a video explaining your answers.