Go playground to conver a quantity of utia to TIA

convert.go

package main

import "fmt"

// utiaPerTia is the number of utia in one TIA
// see https://docs.celestia.org/learn/tia#tia-display-token
const utiaPerTia = int64(1_000_000)

func main() {
	// feel free to modify utia
	utia := int64(1)

	fmt.Printf("%v utia\n", utia)
	fmt.Printf("%v TIA\n", formatAsTia(utia))
}

func formatAsTia(utia int64) string {
	tia := float64(utia) / float64(utiaPerTia)
	return fmt.Sprintf("%.6f", tia)
}

https://go.dev/play/p/5EKFzxn-S23