The egg grading station was the busiest place on the farm. Trays of fresh eggs rolled along a little conveyor belt, and today Spike, Suzy and Little Thunder were in charge.

"Every egg gets weighed," said Suzy, tapping the digital scale. "Then we sort it into the right carton."

Spike read the chart pinned to the wall. "Small eggs are at least 43 grams. Medium is at least 50. Large is at least 59. Extra large is at least 66."

The first egg rolled onto the scale. 61.4 grams.

"Large!" said Little Thunder, and gently placed it in the large carton.

The next was 58.9 grams. Little Thunder reached for the large carton again.

"Wait," said Suzy. "58.9 is less than 59. Only just, but it's still less."

"Medium," said Little Thunder. "Every decimal counts!"

They worked steadily all morning. 67.2 went to extra large. 50.0 exactly went to medium. One tiny egg weighed only 41.8 grams.

"Too small to sell," said Spike. "That one is for our breakfast."

By lunch they had filled a whole carton of twelve large eggs. But the farmer had one more question.

"Is the carton heavy enough to be called large?" asked Spike. "The average needs to be at least 59 grams."

They added up all twelve weights on the calculator. The total was 729.6 grams.

"Now divide by twelve," said Suzy.

Little Thunder pressed the buttons carefully. "60.8 grams!"

"Above 59," said Spike. "This carton passes!"

They checked three more cartons the same way. One medium carton came out at 49.7 grams on average, so they swapped a light egg for a heavier one and checked again: 50.3.

"Fixed," said Suzy.

At the end of the day, the friends stacked the finished cartons into neat towers. The hens clucked from the coop as if to say good job.

"Breakfast?" asked Little Thunder hopefully.

Spike held up the tiny 41.8 gram egg. "One egg between three of us."

"Every gram counts," sighed Little Thunder.