Simple Telephone
by Grace Koh Jialin
#Scienceofplay09
Step back in time and use some old-fashioned technology to make a string phone while learning about sound waves in this fun project with your child.
Skill Level: Intermediate
Suitable For: 4 - 5 years old
Estimated Time: 15 - 30 mins
Environment: Indoors

Learning Framework
Physical - Threading the string to cup, object control (holding the cup)
Intellectual - Exploring how soundwave move
Emotional - Engagement (interaction), sharing feelings through talking
Social - Being able to relate and continue a conversation, build and encourage one another to talk
Materials

Step 1
Make a hole at the bottom of each paper cup using the thumbtack.

Step 3
Tie a knot so that the string doesn’t come out from the cup.

Thumbtack (to help poke holes in the paper cup)
2x Paper Cups
String
Step 2
Put the string through the hole.

Step 4
The simple telephone is ready to use. Move into position with you at one end and your child holding the cup at a distance, making sure that the
string is tight. Make sure the string isn’t touching anything else as well. One person talks into the cup while the other puts the cup to their ear and listens.
Reminder: You have to keep the string straight for best listening quality.
