MIixed Operations With Numbers Up To Seven Digits

1) In a mixed operation involving multiplication and addition or subtraction, do the multiplication first.

Example 1 : 39 + 125 × 7 =

Solution :    39 + 125 × 7
              =  39 + 875
        =  914

2) In a mixed operation involving division and addition or subtraction, do the division first.

Example 2 : 101 – 54 ÷ 9 =

Solution :   101 – 54 ÷ 9

             =  101 – 6

       =  95

3) In a mixed operation involving brackets, do the operation in the brackets first.

Example 3 : (288 + 120) ÷ 12 =

Solution :    (288 + 120) ÷ 12 =

                 = 408 ÷ 12

           = 34

Example 4 : (308 – 72) × (81 – 44) =

Solution :   (308 – 72) × (81 – 44)

              =  236 × 37

        =  8 732

Example 5 : 

There are a total of 200 red pens and blue pens in a box. The number of red pens is 50. A worker packs all the blue pens in equal numbers into 10 plastic bags. Find the number of blue pens in each plastic bag.

Solution: 

• 200 red pens and blue pens in a box

• 50 of them are red pens.

• All the blue pens are packed into 10 plastic bags.

   (200 – 50) ÷ 10

=  150 ÷ 10

=  15

   

The number of blue pens in each plastic bag is 15.