Finding how long something takes when start and end times don't cross an hour boundary (e.g., 2:15 to 2:45 = 30 minutes).
Where your child meets this in real life: Working out how long a TV programme lasts or time left in a lesson
SEAGReady breaks calculate simple time durations into 3 steps, taught in order so each skill builds on the last.
Calculate how long between two times in the same hour by subtracting minutes
Given a start time and duration in minutes, find when it ends (staying within the same hour)
Given an end time and duration in minutes, find when it started (staying within the same hour)
Three free sample questions from our calculate simple time durations course. Every question comes with a full explanation, and hints that guide without giving the answer away.
The clocks show when Sean's swimming lesson starts and finishes. How long does the lesson last?
The first clock shows when Holly starts her homework. She works for 25 minutes. What time should go on the finish clock?
The second clock shows when Olivia finishes her shower. She was in the shower for 20 minutes. What time should go on the start clock?
This is the exact interactive worked example your child sees in SEAGReady. Step through it and watch the method build up.
Zoe's football training starts at 4:10 and finishes at 4:45.
How long does the training last?
4:45 − 4:10
Start time is 4:10, end time is 4:45
Step 1 of 3
Zoe's football training starts at 4:10 and finishes at 4:45.
How long does the training last?
Zoe's training lasts 35 minutes.
The key insight: When times are in the same hour, just subtract the minutes!
Common mix-up: 445 − 410 = 35. Time isn't a regular number. 4:45 doesn't equal 445 because there are 60 minutes in an hour, not 100.
These are the misconceptions we see most often in calculate simple time durations, including the ones our practice questions are specifically designed to catch.
Struggling with calculate simple time durations? The real gap is often in one of these earlier topics.
SEAGReady finds the exact step where your child gets stuck, teaches it with worked examples like the one above, and brings it back for review so it sticks.
Free to start · no card needed