Find the 2 different unit rates and compare them.
$6.45 / 5 m = $1.29 per meter
1 meter
240 cm converts to 249 cm * --------------------- = 2.49 meter
100 cm
and so $3.19 divided by 2.49 meters comes out to $1.28 per meter.
Which is cheaper, $1.28 per meter or $1.29 per meter?