Improving Communication Devices Practice Test

Read how Sofia improved her flag signals. Test showed the flags did not work at night because it was too dark. She added glow sticks to the flags and tested again at night. Her friend saw the glowing flag and answered “yes.” Did the improvement solve the problem?

Read how Emma improved her flashlight code. Test showed white flashes did not work in a bright room. She taped red cellophane on her flashlight, kept 1=come here, 2=yes, 3=no, and tested again in daylight. Now her brother saw the red flashes clearly. What change made the device work better?