You can only unlock the chapter using a special code that we will send you via the Viber app. Receiving a message is free of charge and with no obligations.
My phone number:
Get a code
In compliance with the law, persons under the age of 15 can enter their phone number only in the presence of a parent or guardian.
4-character code:
Check the received code
The page will be refreshed automatically in a few seconds.
To ensure the proper functioning of the website, OpenProf uses cookies that do not store personal data. By continuing to use the website, you agree to cookies. Tell me more »
litres of fuel to cover a distance of 
, calculate:
?
?
. What is the distance between the places on the map if the places in reality are 
apart.
workers make 
products in one hour, How many products would 
workers make in one hour?
bakers make 
cakes in a day, how many cake would one baker make in a day?
, the distance between Ljubljana and Barcelona is 
. What is the approximate distance between places in reality?
flour was used to bake five loaves of bread. How much flour is need to bake two loaves of bread of the same size?
to travel a distance:
?
kg of fruit to make 
litres of drink. How many kg of fruit does the factory needs to make 
litres of drink (round the result to an integer)?
kilograms of pears and 
kilograms of apples for the same amount. How much would a kilogram of pears and a kilogram of apples cost, if the price of a kilogram of apples is 5 monetary units cheaper than pears.
cleaners 
days to clean a factory, how long would it take if three workers got sick after three days?
