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Worksheet Grade 5 Math

Hollowford Filtration Plant: A Grade 5 Decimal Logbook Worksheet

Grade 5 students add, subtract, multiply, and divide decimals to hundredths using a fictional water treatment plant operator's weekly chemical logbook.

Objectives

  1. Students will add and subtract decimals to hundredths from a treatment plant logbook.
  2. Students will multiply and divide decimals by whole numbers to solve plant problems.

Vocabulary

Alum
Alum is the most common chemical that water plants add to make tiny dirt particles clump together. A pinch of alum can help a whole jar of muddy water turn clear.

Also: decimal, hundredths, logbook

Teacher overview

The Hollowford Filtration Plant is a fictional plant used for this worksheet. An operator there keeps a logbook of how much treatment powder is added each day, written in pounds with decimals. This worksheet uses one week of that log to practice adding, subtracting, multiplying, and dividing decimals to hundredths. A common student error is lining up digits by the last place instead of by the decimal point, so remind students to stack the decimal points before adding or subtracting.

Hollowford Filtration Plant: A Grade 5 Decimal Logbook Worksheet — Grade 5 Math
Name: ____________________________ Date: ______________

Student Worksheet

Use the operator's log for the week. All weights are in pounds (lb).

  • Alum added each day: Monday 4.25, Tuesday 3.80, Wednesday 4.50, Thursday 5.15, Friday 3.90.
  • One bag of alum weighs 2.50 lb.
  • The clearwell tank, which stores the cleaned water, read 12.40 ft deep in the morning and 11.85 ft deep at night.
  1. How much alum was added on Monday and Tuesday together?
  2. How much more alum was added on Thursday than on Tuesday?
  3. Find the total alum added from Monday through Friday.
  4. The clearwell dropped from 12.40 ft to 11.85 ft from morning to night. How many feet did it drop?
  5. The operator used 6 bags of alum. Each bag weighs 2.50 lb. What is the total weight?
  6. The plant adds 0.75 lb of chlorine powder each hour. How much is added in 4 hours?
  7. The operator splits 9.60 lb of powder evenly into 4 buckets. How much goes in each bucket?
  8. A jug of liquid alum weighs 10.50 lb. How much does half a jug weigh?
  9. The operator planned to use 25.00 lb of alum for the week. Using your total from item 3, how much is left over?
  10. Explain in one or two sentences why adding the five daily amounts gives the correct weekly total.

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key
  1. Answer: 8.05 lb. Line up the decimal points: 4.25 + 3.80 = 8.05 lb.
  2. Answer: 1.35 lb. 5.15 - 3.80 = 1.35 lb. Subtract by place value after stacking the decimals.
  3. Answer: 21.60 lb. 4.25 + 3.80 = 8.05; 8.05 + 4.50 = 12.55; 12.55 + 5.15 = 17.70; 17.70 + 3.90 = 21.60 lb.
  4. Answer: 0.55 ft. 12.40 - 11.85 = 0.55 ft.
  5. Answer: 15.00 lb. 2.50 x 6 = 15.00 lb.
  6. Answer: 3.00 lb. 0.75 x 4 = 3.00 lb.
  7. Answer: 2.40 lb. 9.60 divided by 4 = 2.40 lb in each bucket.
  8. Answer: 5.25 lb. Half a jug is 10.50 x 0.5 = 5.25 lb.
  9. Answer: 3.40 lb. 25.00 - 21.60 = 3.40 lb left over.
  10. Answer: Adding the five daily amounts works because each day's alum is a separate part of the same week, so the parts add up to the whole week's total.

Differentiation

Support

Give students a printed place-value chart with a marked decimal-point column so they can stack the daily amounts correctly before adding. Work item 1 together as a model, then let students try items 2 and 3 on their own.

Extension

Ask students to design a sixth day for the log with a decimal weight that would bring the Monday-through-Saturday total to exactly 25.00 lb, and show the subtraction that proves their number is correct.

ELL supports

Pre-teach "add," "subtract," "total," and "left over" with a simple picture of a measuring scale and a jar. Provide a sentence frame for item 10: "Adding the daily amounts works because ___."