Question
#28. You are employed as a part-time tutor. A young student of yours was asked to add the following three numbers: 15.6 + 33.36 + 5/8. He changed the fraction to a decimal and lined up the numbers with the last digit on the right as shown here. What was his mistake?
15.6
+ 33.36
+ 0.625
= 410.7
Select an Answer
If you would like to eliminate an answer choice, click the icon to the left of the option.
A
He did not align the decimals
B
He did not correctly translate the fraction into a decimal
C
He failed to carry the extra digits
D
He subtracted instead of adding
E
He did not position the larger number on top
15.6
+ 33.36
+ 0.625
= 410.7
Select an Answer
If you would like to eliminate an answer choice, click the icon to the left of the option.
A
He did not align the decimals
B
He did not correctly translate the fraction into a decimal
C
He failed to carry the extra digits
D
He subtracted instead of adding
E
He did not position the larger number on top
Answers
GPT-4o mini
The student's mistake was **A: He did not align the decimals**.
When adding decimal numbers, it's important to align the decimal points so that the digits in each place value (ones, tenths, hundredths, etc.) are lined up correctly. In this case, if the student had properly aligned the numbers by their decimal points, the addition would have been done correctly.
When adding decimal numbers, it's important to align the decimal points so that the digits in each place value (ones, tenths, hundredths, etc.) are lined up correctly. In this case, if the student had properly aligned the numbers by their decimal points, the addition would have been done correctly.