中考英语复习课件专题四数词.pptx

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1、Special Topic on English Review Courseware for MidClassification of NumbersThe Usage of NumbersConversion of NumbersMistakes in NumbersPractice questions on numbers目录01Classification of NumbersSummary An integer refers to a number without a decimal part,which can be positive,negative,or zero.Detaile

2、d description integers include positive integers(such as 1,2,3),zero,and negative integers(such as-1,-2,-3).The application of integers in mathematics and daily life is very extensive,such as age,quantity,time,etc.Integer A fraction is a number that represents the relationship between parts and the

3、whole,consisting of numerator and denominator.Summary Fractions can represent anything that is not an integer,such as 1/2,2/3,etc.Fractions are very important in fields such as mathematics,science,and engineering because they can accurately represent certain quantities or ratios.Detailed description

4、FractionSummary Decimal is a type of decimal number that can accurately represent fractions or irrational numbers.Detailed description Decimals consist of integer and decimal parts,such as 0.5,3.14,etc.Decimals are very useful in daily life and scientific calculations,such as measuring and calculati

5、ng prices.DecimalVS Percentage is a number that represents the relationship between parts and the whole,usually used to indicate probability or proportion.Detailed description A percentage is a special fraction or decimal commonly used to represent proportion or probability,such as 50%representing a

6、 half probability or 50%discount.Percentages are very common in fields such as business,statistics,and social sciences.Summary wordPercentage02The Usage of NumbersTime expressionSummary:Mastering time expression is a very important part of English learning,which involves the expression of time order

7、,time periods,and time points.Detailed description:In English,time expression is usually expressed on a 12 hour or 24-hour basis.The 12 hour system divides a day into morning and afternoon,while the 24 hour system continuously counts from 00:00 to 23:59.In time expression,it is necessary to master h

8、ow to use prepositions at,in,and on to represent time,such as at 3 oclock,in the morning,and on Sunday.In addition,it is necessary to understand the expression of time periods,such as from 8 to 10,between 9 and 11,etc.Sequential expressionSummary word:Sequential expression is an important way to des

9、cribe the order of events in English,which involves using correct conjunctions and phrases to express the order of events.Detailed description:In English,commonly used sequential conjunctions include first,second,third,etc.Adverbs such as then,after that,in the end,etc.can also be used to describe t

10、he order of events.In addition,it is necessary to master some conjunctions that indicate causal relationships,such as because,so,therefor,etc.When expressing order,attention should be paid to logic and organization to ensure coherence and smoothness between sentences.Divisor expressionSummary:The ex

11、pression of fractions is a special grammar point in English,which involves the correct use of numerators and denominators,as well as the expression of different fraction forms.Detailed description:In English,fractions are composed of numerators and denominators,with denominators represented by cardi

12、nal numerals and numerators represented by ordinal numerals.For example,two-thirds can be expressed as two things,where third is an ordinal word and three is a cardinal word.In addition,it is necessary to master some special ways of expressing scores,such as one in three representing one-third and o

13、ne out of three representing one-third.At the same time,attention should also be paid to the conversion between scores and percentages,such as two fists being equal to 40%.03Conversion of NumbersDecimal conversionSummary:The method of converting decimal numbers to other decimal numbers.Detailed desc

14、ription:When converting decimal numbers to other decimal numbers,certain rules and steps need to be followed.Firstly,determine the target decimal number,then split the decimal number into different bits based on its base and weight table,and convert it according to the weight table.For example,the p

15、rocess of converting the decimal number 25 to a binary number is:25/2=12 remainder 1,12/2=6 remainder 0,6/2=3 remainder 0,3/2=1 remainder 1,1/2=0 remainder 1.Therefore,the binary representation of 25 is 101001.Summary:The method of converting hexadecimal numbers to other base numbers.Detailed descri

16、ption:The conversion method between hexadecimal numbers and other hexadecimal numbers is similar.Firstly,the target hexadecimal number is determined.Then,based on the base and weight table of the hexadecimal number,the hexadecimal number is split into different bits and converted according to the we

17、ight table.For example,the process of converting a hexadecimal number AF to a decimal number is:A 16 1+F 16 0=17*16+15=277.Hexadecimal conversionSummary:The method of converting binary numbers to other base numbers.Detailed description:The conversion method between binary numbers and other base numb

18、ers is similar.Firstly,the target base number is determined.Then,based on the base and weight table of the base number,the binary number is split into various bits and converted according to the weight table.For example,the process of converting binary number 1010 to decimal is:0*2 3+1*2 2+0*2 1+1*2

19、 0=0+4+0+1=5.Binary conversion04Mistakes in NumbersSummary:The usage of zero in English can be complex,especially when dealing with dates,times,and measurementsDetailsIn dates,the absence of a month or day is indicated by th,not 0th or 0In times,00 is used to indicate the hour,not 0For measurements,

20、zero is used to indicate the presence of a quantity,but it should be spelled out as zero instead of 00102030405The Usage of ZeroSummary:Fractions in English are used to express part of a whole or a part of a quantityDetailsFractions are commonly written as two or more words,such as half or three qua

21、rtersWhen writing fractions in numbers,the denominator is written first,followed by a slash(/),and then the numerator For example,2/3Fractions can also be written as decimals,but the meaning may change depending on the context0102030405Usage of fractionsSummary:Decisions are used in English to expre

22、ss fractions that cannot be expressed as whole numbers or fractionsDetailsDecimals are written with a period(.)to separate the integer and fractional parts For example,3.14 reports three points one fourWhen rounding decimals,the appropriate rounding term should be used,such as round up,round down,or

23、 round to the nearestDecimals are also used in measurements,such as temperature and speed,where they provide more precision information than fractions or whole numbers0102030405Usage of decimals05Practice questions on numbersMultiple choice questionsThese questions test the students understanding of

24、 basic numbers such as cardiac numbers(e.g.,one,two,three)and ordinal numbers(e.g.,first,second,third)Multiple choice questions on basic numbersThese questions focus on the students ability to understand and use fractions,including understanding the difference between perfect fractions and mixed num

25、bersMultiple choice questions on fractionsNumerical completion tasks These tasks ask the student to complete a presence or pass by filling in the correct numerical For example,I have _ apps or The class is divided into _ groups.Numerical conversion tasks These tasks ask the student to convert a give

26、n number from one form to another,so as converting a Cardinal number to an ordinal number or vice verseCompletionReading comprehension questions on time These questions ask the student to read a passage about time(e.g.,time zones,telling time)and then answer questions about the passage,such as What

27、is the time difference between New York and Beijing?or How many hours are in a day?要点一要点二Reading comprehension questions on measurement These questions ask the student to read a passage about measurement(e.g.,metric units,converting measures)and then answer questions about the passage,such as How many kilometers are in a mile?or What is the weight of a kilogram in grams?Reading comprehension questions感谢观看THANKS