MATHEMATICS FORM 1 – UNITS

UNITS OF LENGTH

Basic unit of length is meter.

Other unit are such as :-

 
 

 
 

Km hm dam m dm cm mm

1      0      0    0    0   0   0

        1      0    0    0   0    0

     1    0    0   0   0

                        1     0 0   0

                                1 0  0

                                    1 0

                                       1

 
 

 
 

 
 

EXAMPLES

 1. Convert 9.17m into km

 

2. Convert 2/51km into :-

(a) dm (b) mm (c) hm(A)

(a)

(b)

 

 
 

OPERATIONS ON UNIT OF LENGTH

1. Addition

Example Add the following:-

 
 

 
 

Question                                

 1.   Add together the following length (a) 785m, 97m, 605m, (b) 8dam, 9m, 2cm (Give your answer in metre.

 Solution

 

 
 

 

           
     Add

       
               
              SUBSTRATION
                EXAMPLE

perform the following

      

 
 

                MULTIPLICATION
                     EXAMPLES

    

  

         
                
 

           DIVISION

     Perform the following meter.

 
 

      EXAMPLE
   
     

               
  2.   Evaluate 38m ÷ 50 = (Give your answer in centimeter).        

          
           

   3. Find the following in meter
      
              
                                    

                   
                  
                                         

  

EXERCISE

2.   A roil of string ps 8.3 metres long. pieces of string of length 2.30m, 78m, 2.37m and 0.95m are cut off. The remaining part is divided into equal pieces of length 32cm. How many equal pieces are there?

                  
                       

                         There are 19 pieces.

          

           
                        

              

                        
        
                       

                 
                         

OPERATION ON UNITS OF MASS

EXAMPLE

 

 60 seconds         =   1 minutes

 
 

60 minutes           = 1 hour

 
 

24 hour                 = 1 day

 
 

7 days                   =   1 week

 
 

4 week                 =   1 month

 
 

 28, 29, 30 or 31 days = 1 month

 
 

   12 month = 1 year

 
 

                  365 or 366 days   = 1 year

 
 

                  365 or 36 days = 1 year

 
 

Time can be measured by using a clock.

 There are two ways of reading time clock :-

 
 

(i) By reading time in 12 hours

(ii) By reading time in 24 hours. 

EXAMPLES

 1. Change 25 minutes past 10 in the following   using :-

 
 

   (a)   12 hours clock

 
 

   (b) 24 hours closk

 
 

                   Solution:

     (a) 12 hours clock

 
 

                 10:25am

 
 

     (b)   24 hours clock

 
 

          10:25 hours

 
2. Write the following times using a 24 – hours clock :

 
 

(a) 6: 30 am

(b) 9: 45 p.m

. Solution:

 
 

(a) 6:30 a.m it will be in 24 hours is 0630 hours

 
 

(b)   9:45 p.m it will be in 24 hours is 2145 hours.

 
 

3. Write the following times in words using 12 hours clock :-

 
 

(a) 2040

 
 

(b) 2349

 
 

   Solution :

 
 

(a) 08:40 p.m

 
 

     It is forty minutes past eight. Twenty minutes to nine.

 
 

(b) 11:49 pm

 
 

       It is four nine minutes past eleven .

 
 

       Eleven minutes to twelve

 
 

 

 
 

 
 

3.   Write the following times using a 24 hours clock.

 
 

(a)   3:20p.m

 
 

(b)   5:37 p.m

 
 

(c) 70:53 a.m

 
 

Solution

 
 

(a) 1520 hours

 
 

(b) 1737 hours

 
 

(c)   0453 hours

 
 

 
 

 
 

UNIT OF CAPACITY

 The basic unit is litre (l)

 Other unit are:

 
 

 
 

NOTE:

1l   =   1000cm3

 
 

1k   =   10000l

 
 

1?   =   1000ml

 
 

  Conversion of unit of capacity

 EXAMPLES

 
 

Change the following into cm3:-

 
 

(a) 6.5 litre

 
 

(b) 35 litre

EXERCISE

1.   One litre of cooking oil cost sh. 700. Find the cost of 15 litres

Solution:

Sh. 700 x 15 litres

= Tsh 10,500

 
 

 
 

2. Doto sells 1 litre of milk for sh. 100. How many litres of milk should Doto sell to get sh. 34,800?