It is a hot, sunny Saturday morning on the farm. Maya, Duksie and Doobie are helping Mama K in her vegetable garden. The children work all morning.

They dig compost into the soil. They weed and water the garden. Then, they harvest what is ripe.

Today each of the children will take home freshly picked strawberries, spinach and carrots.

Mama K always gives the children a treat for helping her. Sometimes the treat is cake, chocolate, or long sweets that look like snakes. Sometimes it's apples, pears, or oranges.

Mama K has only one rule. "Share it fair!" The children know they must share the treats equally, so they all get the same amount.

Today Mama K has baked a round strawberry cake with pink icing and berries from her garden. The children wait on the grass for their treat.

"Here you go!" smiles Mama K. "But remember the rule that everyone must get the same. Share it fair! Don't fight!"

Maya has the first turn to share the cake. She uses the knife to trace lines in the icing. The others watch her. She does not cut the cake yet. The others must first agree if her way is fair.

"I think I will cut two slices, like this. Now we have three slices, all the same!" Maya shows them.

"No way!" says Duksie, "the one in the middle is much too big!"

Doobie also shakes his head. Maya laughs and shrugs and tells Duksie to try.

"Here! Pass me the knife, I'll do it. Easy peasy!" chants Duksie.

First she rubs out Maya's pattern in the icing and licks her fingers.

Then she makes one cut across and one down. "Look, these are my three slices!"

"That's not fair!" shout Maya and Doobie together.

"Share it fair! The pieces must be the same size and shape," adds Doobie.

"Why don't you try Doobie?" smirks Duksie. "I bet you can't do it!"

"I wish the cake was a square or a rectangle, and then it would be easy!" says Doobie thoughtfully.

"Or, if there were four of us to share the round cake that would also be easy," says Maya.

And then, a picture comes into Doobie's head. He sees the sparkling silver badge at the front of his father's big red truck.

On Sundays he helps his dad to wash the truck, and to polish the shiny badge. "I've got it! I've got it! I know how to do it," yells Doobie.

First he uses a knife to smooth Duksie's lines in the icing. Then he traces three lines on the cake.

It looks just like the badge on his dad's truck, with three equal parts.

"You are full of surprises, Doobie," says Duksie sweetly. "How did you work it out?" Maya asks.

Doobie smiles to himself. For now it is his secret. Later, he will tell his dad.

Just then Mama K comes out of her house. She is carrying a tray with glasses of strawberry juice. "Look Mama K! Doobie found the way to cut the cake into three equal pieces," Maya tells her.

"Well done Doobie, three equal slices! You shared fairly, I'm proud of you all. Now cut the cake and drink your juice. It's time to go home."

Maya cuts along Doobie's lines to make three equal slices.

Just for fun, the children stack the slices on top of each other to check that they are the same size. Yes they are! They pack their cake to take home.

Doobie's dad arrives to pick up the children, and Doobie runs off to meet him.

He can't wait to tell his dad how the badge on the truck helped him to solve a very tricky problem!