I put," one and four are five" and I got it wrong. I know that "to" can mean "is" but I am a little confused,so does this mean that"to" only means "is" or "equal to" when talking about numbers ?
Well, one and four are numbers, but one and four is five. "To" can mean both is or are or many other things, but I guess the English version wants "is" here.
A bit more mathematical phrases would be "Jeden plus cztery to pięć" or "Jeden plus cztery równa się pięć".
Logically "is" is correct. "[The sum of] two and two is four." However, "are" is also used. In fact, there is a Sesame Street song: "Two and two are four. Four and four are eight..." http://www.metrolyrics.com/inchworm-sesame-street-version-lyrics-sesame-street.html
I know that, grammatically, it should be "One and four make five", but can we have "makes" too? A lot of people use the singular verb in sentences like this, even though it's technically incorrect. Besides, I always get marked wrong the first time I get this in a lesson and it's driving me slightly crazy. :)
Okay, I guess it is indeed very common... and actually it was already accepted in every similar sentence apart from this one. So, added here.
Not always. For example, "ain't" qualifies as common, I think, but I doubt many people would claim it's grammatically correct.
It is correct in the dialects where it is common. If Alabama had the most power in the country, this would be seen as "standard" English.
There are so many ways in expressing the same meaning in English such as equals and others that it becomes impossible to pin it down to one. Too much flexibility is often worse than not enough.
Complexity of English, the word run has 645 potential meanings, translation is difficult for this reason. I don't know of any Polish that would come near that.