Garden Detectives · Case 34
The Humming Pump
Short U · Level 6
Short U review with sound comparison and vibration testing

Before reading
Open the case file
Hear the focus words
Read and investigate
The Humming Pump
Read one sentence at a time, then reread for smooth phrasing.
A low hum came from the garden tub when the sun was high. Gus checked the water pump, but its switch was off. The hum stopped whenever a cloud covered the sun. Under the tub sat a black rubber mat.
One corner of the mat touched a metal pipe. The warm sun made the rubber expand a small amount. As it pressed the pipe, water moving through the pipe made the mat vibrate. The broad tub turned that soft buzz into a low hum.
Gus slid a thin cork pad between the mat and pipe. The sun returned, but the tub stayed quiet. He removed the pad for a brief test, and the hum came back. The team had found a vibration, not a hidden pump.
Gus trimmed the mat so it could not touch the pipe. The water continued to run without the hum.
Check the evidence
Can you solve the case?
Choose the answer that is supported by the story.
What really happened?
Sun-warmed rubber pressed a water pipe and vibrated. The tub amplified the faint buzz into a low hum.
For adults
Use evidence, not guesses
Ask the learner to point to the sentence that proves each answer. If decoding is effortful, reread one paragraph at a time. A fluent second reading is more valuable than rushing to the next story.