Out Teach
Material Type:
Lesson Plan
Lower Primary
  • Addition
  • Counting
  • Estimation
  • Math
  • Numbers and Operations in Base 10
  • Out Teach
    Creative Commons Attribution Non-Commercial Share Alike
    Media Formats:

    Education Standards

    Bug Calculations -- Out Teach

    Bug Calculations -- Out Teach


    In this lesson, students use the real-world application of insect monitoring to practice their fluency with addition and subtraction.

    Background for Teachers

    Out Teach logo

    Although this is a math lesson, it presents an opportunity for students to develop some environmental and general scientific literacy. The practice of counting bugs can be very important in agriculture because we need to understand how many pests are present to make decisions about pest management and we also want to know about pollinator bugs so that we can ensure that food crops get pollinated. Students will be looking for and counting bugs, so it is optimal to work this lesson into the fall or spring when there are bugs out and about. The students should be given clear instructions about not touching the bugs so that they are not hurt but you will almost always have students who cannot contain themselves which will present a teachable moment of respecting living things (be ready with consequences that are consistent with indoor practices). You may need to give extra instructions about looking for bugs like telling students to look in the air, gently poke around in the soil and look at all parts of the plants. Squeamish students will need support to work with their groups and can be assured that they don't need to get close to the bugs.

    Key Vocabulary

    • Equation

    • Habitat

    • Pollinator

    • Pest

    • Sum and Difference

    Guiding Question

    How can we use equations to track bug populations in a garden?


    Tell students that they will be finding and tracking bugs today.

    Note: Students are automatically excited about bugs even though some are scared or grossed out. Either way, it should be enough to let them know that they will be finding and tracking bugs during the lesson to get them excited. They will need clear instructions not to touch the bugs and you should anticipate a lot of noise and excitement.

    You may or may not want to model the addition and subtraction process based upon the numbers involved in this activity since it could be very different from any activity students have done before. They will count the bugs in an area and look at the numbers on two different cards. These numbers reveal the number of bugs in that area yesterday and the students have to write an equation to show what happened. For example, if they count 15 bugs and one card says "12," they would write 12+?=15 and solve for the unknown. You can also wait to cover this after the students have finished the exploration to increase the challenge and force higher levels of perseverance and problem solving.


    Have students work in teams to explore a designated area to count the number of bugs they find. Rectangular planting beds work well as do any defined spaces.

    Management Note: If you are using a more open space you will have to give specific instructions for students to know where to go which may require some planning ahead. Give the students a set amount of time to find bugs (3-5 minutes should be good).

    Pass out the number cards to groups while they are counting bugs.

    When you signal, the teams should look at the numbers on their cards and create equations to show how the number of bugs has changed since yesterday.

    Note: Some students may require quick conferencing to connect the abstract concept of a missing variable to the flow of collecting data two days in a row. They will need some practice modeling different equations with different digits to see what is and isn't possible. This will be explained after the exploration so it's ok for them to struggle as long as they aren't completely stuck.

    As students explore, walk to groups of students and ask questions.


    • Where have you looked to find bugs?

    • If the number on your card shows where you started and the number from today shows where you end, how will you write your equation?

    • How do you know that you should add/subtract?


    Gather students to a meeting area by using a call signal that they recognize (loud enough to be heard outside).

    Write their equations on the board, compare them and talk through the different components using math terminology.

    Ensure that students understand the importance of monitoring insects for our food supply as referenced above in "Background for Teachers."

    Questions for digging deeper:


    • Why do you think the number of bugs changes each day?

    • Is there a better way to count bugs in a large area? (estimation)


    Have students work alone or in pairs to write a word problem about anything else in the garden. It must involve addition or subtraction.


    Students can swap their word problems and solve them or solve a final equation about bugs with numbers you give them.

    Extensions and Connections

    This lesson can be connected to both fiction and non-fiction texts regarding insects in Language Arts and it could be very helpful for students to deepen their understanding if these lessons are taught around the same time period.

    There are important standards from NGSS that connect to insects regarding habitat diversity and pollination. Combining those lessons with this math lesson could deepen student learning.


    Hi-Low Number Cards included with the printable lesson plan.