Money Math

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Sub Topics Counting Coins Adding Money  Subtracting Money  Money Math Problems

Addition, subtraction, multiplication, division and various mathematical operations are used in money math problems. For example, David went to a mall and purchased two jeans and 2 shirts and it costs $\$$5400. He doesn't have change. So, he gives $\$$10000, in return he gets $\$$4600. Here, we have used subtraction for calculating money. One more thing is that both currencies must be similar for whatever operation is going to be performed (addition, subtraction, multiplication or division). Money can be both in the coin or note form.

Counting coins includes two processes i.e. sorting and counting. In process of sorting, coins are separated according to their cost. That is, all coins must be collected in separate bins according to their cost. Sorting is done in same manner as the name of the students in class. Then, use counter to count them. In counting process, coins will be counted as they are arranged that is according to their cost. A counter can be used to perform both sorting and counting at the same time.

Let us consider an example to understand the process of coin counting. If we have 700 coins of one penny, 500 coins of dime, 70 coins of quarter and 500 coins of half dollar in a bag. First, sort all these coins according to their cost. Then, count them separately with the help of a counter. For interactive counting coins, actually we can take help of others in counting. For interactive counting coins, divide the coins among several people. Each person can be given a work to count a particular coin. This will make it easy to separate the coins and count them.
Amounts of money can be written in different ways. Addition or collection of money is called as money combination. We can covert money or currency from one form to another. Suppose we wish to find the sum of 100 cents and $\$$50, sum up the cents and dollar by converting the dollar into cents. One dollar equals 100 cents. Cent is the smallest unit of money. All other units can be represented in the form of cents. Money combination includes the money in form of addition with same unit.

Following table shows the relationship between cent and other units.

1 penny	1 cent
1 nickel	5 cents
1 dime	10 cents
1 quarter	25 cents
1 dollar	100 cents

Let us see money combinations using pictures. For example, Let us consider that we are adding a coin group such as

Here, answer in cent can be given by adding all coins after converting them in cents.
As we know that (3 dime + 2 dime) = (3 x 10 cents) + (2 x 10 cents) = 50 cents.
1 quarter = 25 cents
2 pennies = 2 cents.
Then, cents = 50 + 25 + 2 = 77 cents.
Therefore, by converting all the coins into cents, we get in total = 77 cents.
Money can be subtracted as same as we add money. Subtracting money involves subtracting the amounts and placing proper sign on the answer. If money is to be expressed in decimals, then dollars to be in the left of the decimal point and cents to the right of the decimal point. Let us consider an example to understand the concept of subtracting money combinations.

Let us see how much is $\$$44 less $\$$ 22

Taking $\$$22 away from $\$$44, we get $\$$22.

If you have 35 cents and you lend me 12 cents, how money would you have left?

Let X = 35 cents and Y = 12 cents
As x is greater,
X - Y = 35 cents - 12 cents = 23 cents
Given below are some of the money math problems.