Math problem set Grade 1 Math

Room 14's Tap Tally: A Grade 1 Addition and Subtraction Set

Eight grade 1 addition and subtraction problems within 20, built from one classroom's three-category tally chart of hand-washing water-saving checks.

Grade: Grade 1
Subject: Math
Material: Math problem set
Time: 30 min
Prep: No prep
Materials: Counters or linking cubes (optional, for support)

Standards

1.OA.A.1 Common Core Math

Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.

How this material aligns: Every problem uses the tally chart totals to pose add-to, take-from, and compare word problems within 20, with the unknown in different positions, exactly the situations this standard requires.

All materials for 1.OA.A.1 →

1.MD.C.4 Common Core Math

Organize, represent, and interpret data with up to three categories; ask and answer questions about the total number of data points, how many in each category, and how many more or less are in one category than in another.

How this material aligns: The chart organizes hand-washing checks into three categories, Remembered, Forgot, and Helped a Friend Remember, and problems 1 through 3 ask students to interpret totals and compare two categories directly.

All materials for 1.MD.C.4 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-07-15.

Objectives

Students will add and subtract within 20 to answer questions about a class water-saving tally chart.
Students will interpret a three-category tally chart and state how many more or fewer are in one category than another.

Vocabulary

Water conservation: Using less water and using it wisely so there is enough for people and nature now and in the future. Small actions matter, since a faucet dripping once per second wastes roughly 3,000 gallons per year.

Teacher overview

Suppose Room 14, a fictional grade 1 classroom, spent one week keeping a hand-washing tally chart. Every time a student washed their hands, a classmate marked whether the student Remembered to turn off the tap right away, Forgot and left it running for a moment, or Helped a Friend Remember to turn it off. By Friday, the tally chart showed Remembered: 12 checks, Forgot: 5 checks, and Helped a Friend Remember: 3 checks. This problem set uses that one chart for every problem, so students build fluency with addition and subtraction within 20 while reading real data instead of isolated number sentences.

A common misconception in this kind of problem is treating every "how many more" question as an addition problem. Students who see the word "more" sometimes add the two numbers together instead of subtracting to find the difference; watch for this error especially in problems 2 and 5.

Room 14's Tap Tally: A Grade 1 Addition and Subtraction Set — Grade 1 Math

Name: ____________________________ Date: ______________

Problems

Room 14 kept a tap tally chart for one week. Here are the totals. Remembered: 12 checks. Forgot: 5 checks. Helped a Friend Remember: 3 checks.

How many checks are there in all? Add all three groups.
How many more checks were Remembered than Forgot?
How many checks were Remembered and Helped a Friend Remember in all?
Of the 12 Remembered checks, 5 happened before lunch. How many happened after lunch?
The class had a goal of 15 Remembered checks by Friday. Did the class reach the goal? If not, how many more checks did it need?
Suppose 2 more students remembered to turn off the tap on Friday. This was after the chart above was made. What is the new Remembered total?
Use your new total from problem 6. Room 14 wants 20 Remembered checks for the month. How many more does it need?
Tally marks are drawn in groups of five. The fifth mark crosses the first four. The 12 Remembered checks are drawn as tally marks. How many full groups of five are there? How many extra marks are left over?

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 checks. 12 + 5 + 3 = 20.
Answer: 7 checks. Remembered (12) is 7 more than Forgot (5): 12 − 5 = 7.
Answer: 15 checks. 12 + 3 = 15.
Answer: 7 checks. 12 − 5 = 7.
Answer: 3 checks. No, the class did not reach its goal of 15 Remembered checks; it had 12, and 15 − 12 = 3 checks short.
Answer: 14 checks. 12 + 2 = 14.
Answer: 6 checks. Room 14 needs 6 more Remembered checks to reach 20: 20 − 14 = 6.
Answer: 2 groups of five. 12 = 10 + 2, and 10 is two groups of five (5 + 5), leaving 2 extra marks.

Differentiation

Support (below grade level)

Provide counters or linking cubes so students can build each number (12, 5, 3) with objects before adding or subtracting, and let them draw the tally chart's marks on scratch paper to count instead of working from numerals alone.

Extension (above grade level)

Ask students to set their own goal for the "Helped a Friend Remember" category (currently 3) and write one addition problem and one subtraction problem, with answers, about reaching that goal.

ELL supports

Pair each category name (Remembered, Forgot, Helped a Friend Remember) with a simple picture (a hand turning off a tap, a running tap, two children by a sink) on a reference card students can keep on their desks while solving the problems.

Extensions

Have the class keep its own real tap tally chart for one week, using the same three categories, and write a new set of addition and subtraction problems using their own numbers once the week is finished.