Converting Fractions and Decimals — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
2 1/2 written as a decimal is 2.12.
Corrected: 2 1/2 written as a decimal is 2.5.
Grade 5 students convert the fraction part 1/2 to 0.5, then add it to the whole number 2 to get 2.5, not 2.12.
2. Fix the sentence:
3 3/4 written as a decimal is 3.34.
Corrected: 3 3/4 written as a decimal is 3.75.
Grade 5 learners divide 3 by 4 to get 0.75, then add it to 3, giving the terminating decimal 3.75.
3. Fix the sentence:
The decimal 4.25 written as a mixed number is 4 25/10.
Corrected: The decimal 4.25 written as a mixed number is 4 1/4.
Grade 5 students rewrite 0.25 as 25/100 and simplify by dividing top and bottom by 25 to get 1/4.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. The mixed number 5 1/2 written as a decimal is 5.5.
Grade 5 students convert 1/2 to 0.5 and add it to 5 to get the terminating decimal 5.5.
2. The decimal 6.75 written as a mixed number is 6 3/4.
Grade 5 learners simplify 75/100 by dividing top and bottom by 25, giving 3/4 as the fraction part.
3. The mixed number 1 1/4 written as a decimal is 1.25.
Grade 5 students change 1/4 to 0.25, then add it to 1 to get the decimal 1.25.
4. The decimal 2.5 written as a mixed number is 2 1/2.
Grade 5 learners simplify 5/10 by dividing top and bottom by 5 to get the fraction 1/2.
Part C: Short Answer
Answer each question in one or two complete sentences.
1. Explain how to convert the mixed number 4 3/4 to a decimal.
Sample answer: First, change 3/4 to a decimal by dividing 3 by 4, which equals 0.75. Then add 0.75 to the whole number 4 to get the terminating decimal 4.75.
Grade 5 students learn that mixed numbers split into a whole number plus a fraction, and the fraction converts to a decimal by division.
2. Convert 3.5 to a mixed number and explain your steps.
Sample answer: The whole number is 3, and 0.5 equals 5/10. Simplify 5/10 by dividing top and bottom by 5 to get 1/2. The mixed number is 3 1/2.
Grade 5 learners separate decimals into whole and fractional parts, then simplify the fraction to its lowest terms.