Grade 1 Math Book · Addition & Subtraction
Ten Flashing Fireflies
by Philemon Sturges
Two children catch fireflies on a summer night, one at a time. As the jar fills, the sky gets darker, until they decide to let all ten go free.
Why it's useful
Every page shows a different way to make 10, which is one of the most important ideas in first grade.
- Number bonds to 10. 9 in the sky and 1 in the jar, 8 and 2, 7 and 3, all the way down.
- Part-part-whole thinking. The total stays 10 while the parts change.
- Subtraction and addition together. Kids see that taking from one group adds to the other.
Try it in class or at home
- Firefly jar. Use 10 yellow counters, a paper jar and a dark "sky" mat. Move one at a time and say both parts.
- Record the bonds. Write each page as an equation: 7 + 3 = 10.
- Hide and guess. Hide some counters in the jar and ask how many are inside if 6 are still in the sky.