In the school kitchen this morning, the air was filled with anticipation. The children from the Little Bees class were preparing to bake honey cookies with their teacher, Miss Jane. Flour was poured in a large bowl, honey was ready in a glass jar, and on the baking sheet waited cookie cutters shaped like stars and hearts.
"Now, children, who will help me weigh the sugar?" asked Miss Jane and reached for the modern digital scale. She placed a bowl on it, but instead of numbers, only confused lines and the word "ERROR" appeared on the display.
"Oh dear," sighed the teacher. "It seems our scale has broken."
Emma curiously peeked over. "How will we weigh the sugar and other ingredients now, Miss Jane? Without the exact amounts, the honey cookies won't turn out as well."
Matthew wrinkled his nose. "That's a shame. We were so looking forward to this."
Just then, a shiny little figure appeared in the kitchen doorway. It was Richie the robot, a helper for the entire school. He had a kind face with two blue lights instead of eyes and moved on small wheels almost silently.
"Bzzzt. I've detected a problem, friends," announced Richie in a pleasant voice. "Broken scale? That's a challenge! But maybe... maybe we can manage without it."
Emma and Matthew perked up. "Really, Richie? How?" asked Emma.
Richie swayed slightly, as if thinking. His lights blinked. "Click. Have you ever heard of balance and how old-fashioned scales work?"
The children shook their heads. They only knew the digital one that was now on strike.
"Excellent! Let's try to make a simple one. We need something long and straight... for example, this ruler," Richie pointed with his telescopic arm to a wooden ruler lying on the counter. "And something for the ruler to rock on. A small cylinder... ah, here's an unused round pencil!"
Miss Jane smiled. "That sounds like an interesting experiment, Richie. Show us how to do it."
Richie placed the pencil on the counter and carefully positioned the ruler on its center. "Now, Emma, try placing this small eraser on one end of the ruler."
Emma placed the eraser on the edge of the ruler. It immediately tipped over and touched the counter. The other end flew up into the air.
"Oops!" Emma laughed. "It fell down."
"Exactly," agreed Richie. "One side is now heavier. But what happens, Matthew, if you place another eraser that looks exactly the same on the other end of the ruler?"
Matthew took a second, almost identical eraser and carefully placed it on the opposite end of the ruler. The ruler swayed for a moment, but then remained almost horizontal. Only one end was a tiny bit lower.
"Almost!" said Matthew. "But not completely straight."
"Bzzzt. Very good observation, Matthew," Richie praised him. "These erasers aren't completely identical, one might be a little more worn and lighter. But do you see the principle? When there are equal distances from the center – our pencil – and equal weights on both sides, the ruler stays in balance. We call that center, around which it rotates, the axis of rotation or fulcrum."
Richie gently moved one eraser closer to the pencil. The end with the other eraser immediately dropped. "Aha! I changed the distance, and the balance was disrupted, even though the erasers are almost the same." Then he returned the eraser to its original position.
"That's quite fun," said Emma. "But how does this help us weigh flour for the cookies? We need precise grams there."
"Click. Excellent question, Emma," replied Richie. "This is just a simple demonstration model. To weigh more precisely, we need something more stable. What if we used, for example,... a coat hanger and two identical yogurt containers?"
Richie looked around the kitchen and his optical sensors focused on a wire hanger hanging on a cabinet handle. "That will be perfect! And we'll find containers in the recycling bin, wash them, and we can start building our own scale!"
The children eagerly agreed. Miss Jane found a sturdy wire hanger and from the recycling bin they selected two clean yogurt containers. Richie then showed them how to thread string through small holes that Miss Jane carefully made around the edges of the containers, and how to hang them on the ends of the hanger.
"It's important that the strings are the same length and the containers hang at equal distances from the hanger's hook," Richie explained, while Miss Jane hung the hanger on the handle of a tall cabinet. The empty containers balanced nicely.
"It looks like a swing for little bugs!" laughed Matthew.
"Exactly," Richie agreed. "Now we need something whose weight we know, so we can weigh things. Miss Jane, do you happen to have something with the weight written on it? For example, a packet of candies or a small chocolate bar?"
Miss Jane thought for a moment. "Wait... yes! I have a packet of nuts here that I bought for my snack. And it says exactly fifty grams on it!" She pulled out a small bag from her purse.
"Perfect! Click!" Richie was pleased. "Emma, please put that packet of nuts in one container."
Emma carefully placed the nuts in the left container. It immediately dropped lower.
"Now, Matthew, your task will be to slowly add sugar to the other container until both containers are balanced," Richie guided him. "Miss Jane, could you please give him the bowl of sugar and a spoon?"
Matthew concentrated intensely as he scooped sugar with the spoon and poured it into the right container. At first nothing happened, but as more sugar was added, the container with nuts began to slowly rise.
"A little more... more... careful, slowly," Emma advised.
Matthew added one last small spoonful and... both containers hung at almost exactly the same height!
"We did it!" the children exclaimed together.
"Bzzzt! Excellent, Matthew! Now we have exactly fifty grams of sugar in this container," Richie praised him. "If we need more, we simply pour this sugar into the bowl and repeat the process."
Miss Jane clapped. "Children, you are wonderful helpers and inventors! And you, Richie, have helped us so much. Not only will we have honey cookies, but we've also learned something new about balance and weighing."
The children smiled from ear to ear. Together they then used their new hanger scale to weigh the other necessary ingredients. The dough smelled wonderful of honey and spices, and soon the sweet aroma of baking began to spread from the oven. While the honey cookies were baking, Richie told the children more about how similar scales were used by people long ago, when they had no electricity or digital devices.
"You know, children," Richie said when the aroma became irresistible. "Egyptian merchants or Roman builders, they all needed to weigh very precisely. They built enormous pyramids and temples! And they had no batteries or displays. Everything worked on the principle of balance, levers, and weights."
Emma imagined large stone scales in ancient Egypt. "It must have been complicated to build such big things without computers!"
"Bzzzt. It was different, but people were inventive, just like you today," Richie smiled with his little lights.
Just then there was a ding from the oven. "The honey cookies are ready!" called Miss Jane and carefully, with oven mitts, pulled out a tray full of golden-brown, fragrant honey cookies.
"Hooray!" the children cheered.
When the honey cookies cooled a little, Miss Jane allowed them to take one each. Emma chose a star, Matthew a heart.
"Yum, they're delicious!" said Matthew with his mouth full. "And we weighed them on our hanger scale!"
"Exactly," Miss Jane smiled. "You see, even when something breaks, you can always find a solution if we work together and use our heads. And our scale today was not only useful, but also fun, wasn't it?"
The children nodded, munching on the sweet honey cookies.
Richie approached them. "Click. Today you learned that even simple things around us, like a ruler or a hanger, can hide interesting principles. And that the best tools are often those we create ourselves or understand how they work." His blue lights winked cheerfully. "The world is full of such little mysteries and discoveries. You just need to look carefully and try."
Miss Jane hugged both Emma and Matthew. "I'm very proud of you. Not only did you bake wonderful honey cookies, but you also became little scientists and inventors."
And what about you, children? Will you also try to build a simple scale from a hanger and containers at home with your parents? You might be surprised by everything you can weigh and discover with it!