Englishfor English speakers
interval
Noun
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A distance in space or in time.
There is a ten-minute interval between classes.
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In music, an interval is the difference in pitch between two notes.
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In mathematics, an interval is a connected section of the real line.
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(mostly British) An intermission.
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In the game of cricket, either of the two breaks, at lunch and tea, between the three sessions of a day's play.
arithmetic
Noun
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The kind of mathematics in which addition, subtraction, multiplication, and division are done on numbers.
My son is starting to do simple arithmetic like math2 + 2 = 4/math.