最新加法运算定律练习题
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加法运算定律练习题
一、判断题。
1. 27+33+67=27+100 ()
2. 134-75+25=134-(75+25)()
3. 先加前两个数,或者先加后两个数,和不变,这是加法结合律。()
4. 56+72+28=56+(72+28)运用了加法交换律。()
二、怎样简便就怎样计算(35分)。
355+260+140+245 645-180-245
365+64+36 43+169+57 456+(92+44)361+72+439+128 (24+65)+(35+30+46)
730+895+170 820-456+280 900-456-244 89+997 103-60 458+996 876-580+220 997+840+260 956—197-56
三、解决问题.
1.修路队三个月修完一条路.第一个月修38千米,第二个月修25千米,第三个月修62千米.问:这条路一共长多少千米?
2.商店卖出了5台同样的热水器,由于优惠金额不等,售价分别为2280元、2160元、2120元、2300元、2040元.问:这5台热水器的平均售价是多少元?
3.同学们搬砖维修花园,高年级同学每人搬4块,五年级有学生323人,六年级有学生377人.问:同学们一共搬了多少砖?(用两种方法解答).
4.有两个数分别是321和609,把第一个数加上3,同时把第二个数减去3,多少次后两个数相等?
加法结合律:先把前两个数相加,或者先把后两个数相加,和不变。(1)63+16+84 (2)76+15+24 (3)140+639+860
(4)46+67+54 (5)680+485+120 (6)155+657+245
减法交换律:如果一个数连续减去两个数,那么后面两个减数的位
置可以互换。字母表示:a-b-c=a-c-b
(1)198-75-98 (2) 956—197-56
减法结合律:如果一个数连续减去两个数,那么相当于从这个数当
中减去后面两个数的和。
字母表示:a-b-c=a-(b+c)
(1)369-45-155 (2)896-580-120 (3)900-456-244 拆分法:当一个数比整百、整千稍微大一些的时候,我们可以把这个数拆分成整百、整千与一个较小数的和,然后利用加减法的交换、结合律进行简便计算。例如:103=100+3
(1)89+106 (2)103-60
凑整法:当一个数比整百、整千稍微小一些的时候,我们可以把这个数写成一个整百、整千的数减去一个较小的数的形式,然后利用加减法的运算定律进行简便计算。例如:97=100-3,998=1000-2 (1)56+98 (2)658+997
(3)458+996 (4)89+997
谓语动词单复数的使用规则
一般every, each后用单数;all 后面的名词是复数.
1)名词性从句及不定式、动名词作主语时,谓语动词一般用单数形式。【例如】To finish the work in advance is what he wants.
Smoking cigarettes is dangerous to your health
What seems easy in theory is difficult in practice. What caused the accident is a complete mystery. 但是,what引导名词从句作主语时,其表语是复数形式时,系动词也可以是复数形式。【例如】What we badly need here are qualified teachers.
2)当主语是单数,后面跟着由including, with, together with, along with, like, in addition to, as well as, rather than, but, except, more than, accompanied by 等连接的短语时,谓语动词用单数。【例如】Mary as well as her sister likes listening to music. Doctor Richards, together with his wife and three children, is to arrive on the afternoon flight. My best friend rather than anyone else has got the first prize in the speech contest.
3) one, one of, every, everyone, everybody, each, many a, either, neither, no one, nobody, anyone, anybody, someone, somebody用作主语或修饰主语时,谓语动词用单数形式。【例如】Each man, woman and child has the same right. Many a student doesn’t like to do their homework. (many a student=many students) Either of students is going to compete for the president of the students’ union.
More than one person was involved in the case. Neither of the young men who had applied for a position in the university ____.
A) has been accepted
B) have been accepted
C) was accepted
D) were accepted neither用作主语或修饰主语时,谓语动词用单数形式。此外,定语从句用过去完成时,主句应用一般过去时,故答案为C。