Math practice · reimagined
Unit Conversion Game
This unit conversion fight swaps days for hours, kilograms for grams and 54 km/h for 15 m/s, and asks for the minutes between two clock times. Switch units before your rival can, and every right answer becomes a strike.
Ages 4–99+ · no download · plays in your browser · 23 languages
What is unit conversion?
Unit conversion means writing the same amount in a different unit, such as minutes instead of hours. The amount itself does not change, only the size of the pieces you count it in. One hour holds 60 minutes, so a 3-hour car trip is also a 180-minute trip.
Example: how many minutes is 420 seconds?
- On screen the problem reads 420 s = ? min, so seconds go in and minutes come out.
- A minute is much longer than a second, so the answer will be a much smaller number.
- Each minute holds 60 seconds, and 7 × 60 = 420, so 420 seconds make exactly 7 minutes.
- So the answer is 7 minutes, and 7 is what you type.
Learn it step by step
Trading between metric units — and the metric system loves the number 1000.
1 km = 1000 m and 1 kg = 1000 g. To go from the big unit to the small one, multiply by 1000 (3 kg = 3000 g); to go back up, divide by 1000. Just slide the digits and keep track of the unit you're asked for.
Tips and common mistakes
- Remember: big unit, small number. 240 seconds shrink to just 4 minutes, while 5 days grow to 120 hours. Check which way the number should move before you type.
- A common mistake is reading m as minutes. Here m is a metre, a length, and min is a minute, so 4000 m = ? km is about distance.
- Turn the weekly shop into a metric units game. Read the weight on each packet, say it in the other unit, then line the packets up from lightest to heaviest.
How to play
Each round asks for an amount in a new unit, such as 6 h = ? min or 7000 g = ? kg, or for the minutes from 4:20 to 5:00. Type the answer on the keypad; it is always a whole number. If yours arrives first, Tomato attacks, and a quicker answer hits harder.
— Quick answers —
Units: the short FAQ
- What does m/s mean?
- The symbol m/s means metres per second, the distance something covers in one second. Its partner km/h means kilometres per hour. Both measure speed, so one can be turned into the other. At 18 km/h you travel 18000 metres in 3600 seconds, which is 5 metres every second. So 18 km/h is the same speed as 5 m/s.
- How do you convert days to minutes?
- To convert days to minutes, go through hours in two steps. First multiply by 24, because a day has 24 hours. Then multiply by 60, because each hour has 60 minutes. So 3 days are 3 × 24 = 72 hours, and 72 × 60 = 4320 minutes. Two small steps are easier to check than one big jump.
- How do you remember how many seconds are in an hour?
- An hour has 3600 seconds, and you can rebuild that number instead of memorising it. A minute is 60 seconds and an hour is 60 minutes, so an hour is 60 groups of 60 seconds: 60 × 60 = 3600. For a mixed time, convert each part and add them: 1 h 20 min is 3600 + 20 × 60 = 4800 seconds.
- Why does my child find elapsed time so hard?
- Elapsed time, the minutes that pass between two clock times, is hard because an hour has 60 minutes, while ordinary numbers count in tens and hundreds. A child who treats 4:50 and 5:20 as 450 and 520 gets 70 minutes. Counting on avoids the trap: 10 minutes reach 5:00, then 20 more reach 5:20, so the answer is 30.
- Can my class practise converting units here for free?
- Yes, all four levels cost nothing: pupils open the page on any laptop, tablet or phone and start without signing up or downloading anything. For ten minutes of measurement conversion practice, write 3 km, 5000 g and 8 kg on the board. Pupils sort them into lengths and masses, then rewrite each one: 3000 m, 5 kg, 8000 g. To follow every pupil over the term, the schools plan brings a teacher dashboard, priced per student.