Math Bell Ringers for Grades 9–12
This page collects every math bell ringer we have posted for grades 9–12: 2 bell ringers so far, newest first, with a new one added each school day. Each is a 3–5 minute warm-up for high school students covering quick problems with worked answers: fractions, percents, equations, probability and more. The answer and teacher notes sit in the collapsed box under each prompt, so you can project the page without giving anything away.
Comparing two-dice probabilities
You roll two fair six-sided dice and add the numbers. Which is more likely: a sum of 7 or a sum of 10? Give the probability of each as a fraction in lowest terms.
Answer and teacher notes
There are 6 × 6 = 36 equally likely outcomes.
Sum of 7: (1,6), (2,5), (3,4), (4,3), (5,2), (6,1) = 6 outcomes, so 6/36 = 1/6.
Sum of 10: (4,6), (5,5), (6,4) = 3 outcomes, so 3/36 = 1/12.
A sum of 7 is twice as likely as a sum of 10. Check: 1/6 = 2/12. The most common error is counting (4,6) and (6,4) as the same outcome; on two separate dice they are different.
Solving a linear equation
Solve for x, then check your answer: 3(x − 4) = 2x + 5
Answer and teacher notes
3x − 12 = 2x + 5 → x − 12 = 5 → x = 17
Check: 3(17 − 4) = 3(13) = 39, and 2(17) + 5 = 39. Both sides match. The most common error is distributing the 3 to x only and writing 3x − 4.
Free to use. Copy, print, project or adapt any of these for your students. If you share them online, please credit Daily Bell Ringers with a link. Not for resale. License: CC BY-NC 4.0.
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Want more? See our ready-made list of math bell ringers and how to run bell ringers in high school, or make a custom one with the free bell ringer generator.