A Complete these sentences according to the clues in brackets.
1._______ ________ _________,people counted numbers in tens.《在古代》
2.Can you write these numbers ______ _______ _______?
3.The picture _________ ___________amodern calculator.《代表》
4.A computure can do a calculation _______ ________ ________.非?？?br/>5.It is an abacus.改為復數(shù)句子
__________ __________ ___________
6.The little girl knows two languages.劃線的句子提問
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___________ _________ languages __________ the little girl ___________?
7.My phone number is 25865281.對劃線句子進行提問
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_______________your phone number?
8.Use your own computer.改為否定句
_______ _______ your own computer.
9.A computer can do a calculayion in a flash.改為一般疑問句
_________ a computer ________a clculation in a flash?
10.The abacus in the picture shows a number.對劃線部分提問
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________ _________shows a number?
11 David is from Thailand.改為同義句
David______ ________ Thailand.
12 The beads on the wires show ones,tens,hundreds and thousands.改為同義句
The beads on the wires_______ _______ ones,tens,hundreds and thousands.
13 This was a very important invention.改為感嘆句
_________ __________important invention it was!
Rewrite these sentences with the help of the words in brackets.
1.multiply 4 by 5,and you will get 20.
2.Add 3 and 9,and you’ll get 12.
3.Subtrct 2 from 10,and you’ll get 8.
4.Divde 8 by 4 ,and you’ll get 2.
5.Keep quiet,please.
快,人在
畫線部分：
7.25865281
6.two
10.in the picture