Subtracting times

In my 7 year old’s math class, they’re learning about time. In particular, they’re learning how to figure out how many hours and minutes are between two times. For example: If it’s 1:45, how long until it’s 5:18? They way they are taught is by counting up by hours until you get within one hour, and then count up by minutes. Something like this: This seems like a totally great way to explain it.…