His newfound confidence stimulated him to go at arithmetic problems with a new spirit.

他重新找回的自信鼓舞他用一种新的精神去解决算术问题。

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He likes to study arithmetic, and he can do all of the arithmetic problems in his book easily.

他喜欢学数学，课本上所有的数学问题他都能不费劲地解答。

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He is studying some arithmetic problems.

他正在研究一些算术问题。

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Psychologists had 543 men and women in a mall, ages 25 to 75, take a test that involved quickly evaluating whether a series of arithmetic problems had been properly solved.

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Samson and I worked together through a few problems, from arithmetic to trigonometry, and I have to say that the estimations required were eminently fair.

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