~ MATH ACTIVITY BOOK REVIEW 1 ~

Dear Angels,

Below are the answers. Please go through them and learn from your mistakes. Do not repeat them in your exams!  =)


Math Activity Book 4A Part 1 (Pg.95 - 109)

1. 30 336 ,  40593


2. Ten thousand, two hundred and fifty
     Eighty-four thousand, three hundred and seventy-six


3. 11 301 , 25 219,  90 005


4a. 70
4b. 70 000
4c. 7000
4d. 700


5a. 50424
5b. 75 210


6a. 50 000
6b. 900
6c. 30 412
6d. 25 061


7a. 50 758, 50 785, 50 870, 50 875
7b. 804, 10 004 , 12 004, 40 804, 14 004


8a.   $680 , $700
        $790 , $800
        $1560 , $1600
        $2600 , $1600


b. Any answer from 25m to 29m  or 31m to 34m


9.  2 X 8  ,  4 X 4  ,  1 X 16
     2 X 10,  4 X 5  ,  1 X 20


a) The factors of 16 are 1, 2, 4, 8, 16
b) The factors of 20 are 1, 2, 4, 5, 10, 20
c) The common factors of 16 and 20 are 1, 2, 4


10. The first 12 multiples of 5 are 5, 10, 15, 20, 25, 30, 35, 40 , 45, 50, 55, 60

The first 12 multiples of 6 are 6, 12 , 18, 24, 30, 36, 42, 48, 54, 60, 66, 72.


b. The first two common multiples of 5 and 6 are 30 and 60.


11a.  2046
11b.  9920
11c.  19 122


12a.  500 x 4 = 2000
12b.  500 x 4 = 2000
12c.  504 x 4 = 2016
12d. Any answer as long as your answer makes sense


13a. 480 / 6 = 80
13b. 3500 / 7 = 500
13c. 6300 / 9 = 700


14a.  2314
14b.  2125
14c.  2164


15a.  934 R3
15b.  1276 R2
15c.  1141 R3
15d.  625 R5


16a.  470 , 4700 , 100
16b.  650,  6500  , 100
16c.  500 ,  5000


17a. 2700


17b.    58
         x26
         348
       1160
       1408 


17c.   378
         x 47
        2646
      15120
      17766



18a.  30 x 70 ,    2100
18b.  100 x 30,   3000


19a.  11/5
19b.  25/7
19c.  35/8


20a. 4 1/3
20b. 7 1/2
20c. 4 1/4



21a.  7 1/2
21b.  1 2/9
21c.  1 1/2
21d.  1 1/3
21e.  1 8/9
21f.   3 1/4



22a.  1 3/7
22b.  2 2/9
22c.  0
22d.  1 1/8
22e.  2 3/10
22f.   2 1/6



23a.  Shade 8 spades
23b.  Shade 6 spades


24a.  1/8  X  16 = 2

         3/8 X 16 = 48/8 = 6



24b.  1/5 X 25 = 25/5 = 5
     
         3/5 X 25 = 75/5 = 15



25)  9330  divide by 6  = 1555
       His monthly salary is $1555.


26)   Number of pupils --->  1265 - 45 = 1220
        2 Units  -----> 1220  - 130  = 1090
        1 Unit -------> 1090 /  2  = 545

         There were 545 girls.



27a)   3/5  +  3/10    =  6/10  +  3/10   =  9/10

         He completed 9/10 of the job before evening.


27b)  1  -  9/10  = 1/10  

               1/10 of the job was completed in the evening.



28a)   1/2   +  1/8   =  4/8   +  1/8    =  5/8
 
           She poured out 5/8 L of mineral water altogether.



28b)   5/8  +  5/8  =  10/8  = 1 2/8  =  11/4

          11/4 L of mineral water was in the bottle at first.



29)  1 unit ---> $48
       5 units ---> $48  X  5  = $240

        Her total savings is $240



30a)   1   -   3/4   =   1/4
          1/4 of the buns were left.

30b)    3/4  X  40   =  120/4   =  30
                 The children ate 30 buns.