A Complete these sentences according to the clues in brackets.

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 _______ ________ ________.非常快
5.It is an abacus.改为复数句子
__________ __________ ___________
6.The little girl knows two languages.划线的句子提问
----
___________ _________ languages __________ the little girl ___________?
7.My phone number is 25865281.对划线句子进行提问
--------------
_______________your phone number?
8.Use your own computer.改为否定句
_______ _______ your own computer.
9.A computer can do a calculayion in a flash.改为一般疑问句
_________ a computer ________a clculation in a flash?
10.The abacus in the picture shows a number.对划线部分提问
--------------
________ _________shows a number?
11 David is from Thailand.改为同义句
David______ ________ Thailand.
12 The beads on the wires show ones,tens,hundreds and thousands.改为同义句
The beads on the wires_______ _______ ones,tens,hundreds and thousands.
13 This was a very important invention.改为感叹句
_________ __________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
画线部分：
7.25865281
6.two
10.in the picture