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Math problem set Grade 3 Math

Bramblewood Reclamation Log: A Grade 3 Add and Subtract Set

A grade 3 problem set where students add and subtract three-digit liter totals within 1000 from a fictional water reclamation plant's daily test log.

Objectives

  1. Students will add and subtract three-digit liter totals within 1000.
  2. Students will regroup across place values when adding or subtracting.

Vocabulary

Key words: add, subtract, regroup, reclamation

Teacher overview

Bramblewood Water Reclamation (a fictional plant) cleans used water and runs small test batches in its lab each day. A worker writes the liters cleaned in a daily log, and this set uses that log for addition and subtraction within 1000, the core grade 3 place-value skill. Every total stays under 1000 so the numbers match what third graders add and subtract fluently. A common error is forgetting to regroup, so several problems require carrying or borrowing across a place, and the answer key shows the regrouping step by step.

Bramblewood Reclamation Log: A Grade 3 Add and Subtract Set — Grade 3 Math
Name: ____________________________ Date: ______________

Problems

Here is the plant's daily log in liters.

Day Liters cleaned
Monday 320
Tuesday 250
Wednesday 180
Thursday 240
Friday 355
  1. How many liters were cleaned on Monday and Tuesday in all?
  2. How many liters were cleaned on Wednesday and Thursday in all?
  3. How many more liters were cleaned on Monday than on Wednesday?
  4. The plant wanted 900 liters over Monday, Tuesday, and Friday. Add those three days. Did the plant reach 900, and by how many liters over?
  5. How many more liters were cleaned on Friday than on Wednesday?
  6. How many liters were cleaned on Thursday and Friday in all?
  7. How many more liters were cleaned on Friday than on Thursday?
  8. How many liters were cleaned on Monday, Wednesday, and Thursday in all?
  9. A worker wrote that Tuesday and Thursday together make 590 liters. Add to check. Is the worker right?
  10. On Monday and Tuesday the plant cleaned 570 liters together. It wants to reach 800 liters. How many more liters are needed?

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: 570 liters. 320 + 250 = 570 liters.
  2. Answer: 420 liters. 180 + 240 = 420 liters.
  3. Answer: 140 liters. 320 − 180 = 140 liters; borrow from the tens because 2 tens minus 8 tens needs regrouping.
  4. Answer: 25 liters over. Add: 320 + 250 + 355 = 925 liters. Then 925 − 900 = 25, so the plant reached the goal by 25 liters.
  5. Answer: 175 liters. 355 − 180 = 175 liters; borrow across the tens to subtract.
  6. Answer: 595 liters. 240 + 355 = 595 liters.
  7. Answer: 115 liters. 355 − 240 = 115 liters.
  8. Answer: 740 liters. 320 + 180 + 240 = 740 liters.
  9. Answer: No. 250 + 240 = 490 liters, not 590, so the worker's total is wrong.
  10. Answer: 230 liters. 800 − 570 = 230 more liters are needed.

Differentiation

Support

Give students base-ten blocks or a place-value chart with columns for hundreds, tens, and ones so they can line up each three-digit number before adding or subtracting. Model the regrouping in problem 3 with blocks, then let students solve problems 1, 6, and 7, which need no regrouping, before the harder ones.

Extension

Ask students to find two days from the log whose totals come closest to 500 liters without going over, and to prove it with addition. Have them make up a new day for the log so that Monday plus that day equals exactly 600 liters, and explain how they chose the number.

ELL supports

Pre-teach "log," "cleaned," "regroup," and "in all" with a picture of a daily chart. Provide a place-value mat labeled in the students' home language where possible. Let students say each three-digit number by its hundreds, tens, and ones ("three hundreds, two tens, zero ones") before they compute.