4th grade (Unit 1) - HoursOnline version 4th grade (Unit 1) - Hours by Oscar Del Estal Martínez 1 Group 1 2 Group 2 3 Group 3 4 Group 4 5 Group 5 1 hour 60 minutes 60 seconds 1 minute 24 hours 1 day 7 days 1 week 365 days 1 year