Math problem set Grade 1 Math
Clearwater Creek Cleanup Day: A Grade 1 Litter Count Problem Set
A grade 1 math problem set using a three-category litter tally from a creek cleanup day, asking students to find totals and compare categories from one day's counts.
Objectives
- Students will find totals and differences from a three-category tally chart.
- Students will identify which category has the most and which has the least.
Vocabulary
Key words: litter, plastic, cans, category
Teacher overview
A cleanup crew at Clearwater Creek meets once a month to walk the bank and collect litter before it can wash into the water, sorting every piece they find into three bins: plastic, paper, and cans. Doing this every month lets the group compare visits and notice whether one kind of litter keeps showing up more than the others near the picnic area by the footbridge. This problem set gives students one finished tally from a single cleanup day and walks through eight questions about that same data, each one asking students to look back at the same three numbers in a new way. A common misconception in this set is assuming the biggest number in the chart must be the answer to every question; problem 4 asks how many fewer cans than plastic, a difference between two categories rather than the largest count, so students have to reread which two categories the question is actually comparing before they subtract.
Problems
The crew found 7 plastic, 9 paper, and 4 cans on Saturday.
| Litter | Number found |
|---|---|
| Plastic | 7 |
| Paper | 9 |
| Cans | 4 |
- How many items in all?
- How many more paper than plastic?
- How many more paper than cans?
- How many fewer cans than plastic?
- Which litter was the most?
- Which litter was the least?
- Put all plastic and cans in one bag. How many items in the bag?
- Find 3 more cans. How many cans now? How many items in all now?
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Answer Key
- Answer: 20 items. 7 + 9 + 4 = 20.
- Answer: 2 items. 9 - 7 = 2 more paper items than plastic items.
- Answer: 5 items. 9 - 4 = 5 more paper items than cans.
- Answer: 3 items. 7 - 4 = 3 fewer cans than plastic items.
- Answer: Paper. Paper had 9 items, the highest count on the chart.
- Answer: Cans. Cans had 4 items, the lowest count on the chart.
- Answer: 11 items. 7 + 4 = 11 items go into the recycling bag.
- Answer: 23 items in all. The cans go from 4 to 7 (4 + 3 = 7), and the new total is 20 + 3 = 23 items.
Differentiation
Support
Provide a printed bar of 20 squares that students can color in by category (7 for plastic, 9 for paper, 4 for cans) before answering problems 2 through 6, so every comparison question has a picture to point to instead of only numbers to hold in mind.
Extension
Ask students to invent a fourth category, glass, give it a count of their own choosing, and rewrite the answers to problems 1, 5, and 6 using the new four-category chart, checking that their new total still adds up correctly.
ELL supports
Pair each litter word ("plastic," "paper," "cans") with a simple picture icon that stays posted during the problem set, and allow students to answer problems 5 and 6 by circling the correct picture instead of writing the word. Read every problem aloud once before students begin working on their own.
Extensions
Have students design a one-page poster asking visitors at Clearwater Creek to put trash in the right bin, using the tally numbers from this problem set as a reason the sorting matters.