Mathematics Magazine for Grades 1-12  

Grade 3  

Theory: 

Change Due

Change is the money a customer receives back when they have made a purchase. Often the customer gives the merchant more money than the amount due because the customer may not have the exact coins and bills that are needed. The merchant determines how much extra was paid and returns the excess which is called change.
How to find the least number of coins to give in change:Determine the total amount of change due.
Start with the highest denomination of coins or bills
Use as many of this coin as possible without exceeding the amount of change due Repeat this process with the next lowest denomination of coin or bill
Example of making change for purchase of $2.11 and customer paying with a $20.00 bill
Determine change due -- $20.00 - $2.11 = $17.89Get one $10 bill but two would be too much -- have $10.00 for change
Get one $5 bill but two would be too much -- have $15.00 for change
Get two $1 bills but three would be too much -- have $17.00 for change
Get 3 quarters but four would be too much -- have $17.75 for change
Get 1 dime but two would be too much -- have $17.85 for change
Get 0 nickels - even one would be too much -- have $17.85 for change
Get 4 pennies - 5 would be too many -- have $17.89 for change

Solutions from the Previous Issue:

Solve the following sums:

Calculate:

1.        (16 – 8) x (27 : 3) =

Solution:

(16 – 8) x (27 : 3) = 8 x 9 = 72

2.        (51 – 9) : (12 – 5) =

Solution:

(51 – 9) : (12 – 5) = (42) : (7) = 6

3.        (54 : 9) x (72 : 9) =

Solution:

(54 : 9) x (72 : 9) = (6) x (8) = 48  

4.        (63 : 9) x (86 – 78) =

Solution:

Proposed Exercises:

Calculate

1.       

2.       

3.       

4.     

Proposed by Alexandru   Rosu, St. John Bosco School, Grade 3, Brampton, Ontario, Canada