Lesson 2: Mental Subtraction Strategies with Decimals — Practice Questions

1. 1. Use the partial differences method to solve the subtraction problem. What is the value of $8.79 - 3.45$? Answer: ___

2. 2. When calculating $7.95 - 2.61$ using the partial differences method, what is the correct first step?

   • A. $7.95 - 2$
   • B. $7.95 - 0.6$
   • C. $7.95 - 0.01$
   • D. $5.95 - 0.6$

3. 3. A ribbon is $14.6$ inches long. If you cut off a piece that is $5.27$ inches long, how long is the remaining ribbon? Use partial differences to find the answer. Answer: ___ inches

4. 4. To find $6.84 - 2.51$, the first step is $6.84 - 2 = 4.84$. What is the result after completing the next step in the partial differences method?

   • A. 4.34
   • B. 4.83
   • C. 4.33
   • D. 2.33

5. 5. Using the partial differences method, calculate the value of $18.95 - 7.82$. Answer: ___

6. 6. A roll of ribbon is 42.5 meters long. A piece measuring 18.73 meters is cut from it. How many meters of ribbon are left? ___ meters

7. 7. A new video game costs 59.95 dollars. A classic board game costs 34.50 dollars. How much more expensive is the video game than the board game?

   • A. $25.45
   • B. $24.45
   • C. $35.45
   • D. $94.45

8. 8. A rain barrel contained 85.4 liters of water. If 12.5 liters were used for gardening and 28.15 liters evaporated, how many liters of water remain? $\_\_\_ $liters

9. 9. A chemist has a 4.5-liter container of acid. She uses 2.8 liters for an experiment. Which statement correctly compares the amount of acid used to the amount remaining?

   • A. The amount used is greater than the amount remaining.
   • B. The amount used is less than the amount remaining.
   • C. The amount used is equal to the amount remaining.
   • D. The relationship cannot be determined.

10. 10. The length of a python is 4.72 meters, and the length of a garter snake is 0.8 meters. Let $d$ be the difference in their lengths. Find the value of $d$. $\_\_\_$ meters