Ren knelt on the kitchen tiles with string, tape, and blue chalk. He looked at Sam and said, “Big numbers can feel slippery. So let’s build a time map you can walk.”

Chairs scraped, boxes bumped, and Mina zipped by in her red sneakers, waving her magnifying glass. Grandma Noor held the back door wide while Ren stretched the string through the hall and living room.

“From this tile to the garden,” Ren said, tapping the floor, “we’ll follow Earth’s whole story.” Sam touched the line with one finger and smiled.