Many times in day to day life we need to deal with more than one operation. Only addition or subtraction does not help, and we need to make use of a combination of operations in order to solve the problem.
For example:
- Tyler buys one box of chalk costing \($4\) and one pack of pens costing \($2\). He pays \($10\). How much money does he get back?
- In the given example Tyler paid for two items:
one box of chalk \(=$4\)
and one pack of pens \(=$2\)
- To calculate total cost of two items we will add the cost of both the items.
Total cost \(=$4+$2=$6\)
But, Tyler paid \($10\).
- In order to calculate how much money he gets back, we will subtract the total cost of items from the amount he paid.
\(\Rightarrow\;$10-$6=$4\)
- Thus, Tyler gets \($4\) back.
Many times in real life problems we need to deal with more than one operations. Only addition or only multiplication would not help. We need to make use of the combination of operations in order to solve the problem.
For example:
- Amy needs to purchase \(8\) notebooks at \($2\) each and \(7\) sketchpads at \($1\) each. About how much will she spend?
- In the given example cost of one notebook is \($2\) and cost of one sketchpad is \($1\).
- We need to find out costs of \(8\) notebooks and \(7\) sketchpads.
- In order to calculate the above, we will multiply the cost of one notebook by \(8\)
\(=8×$2\)
\(=$16\)
and cost of one sketchpad by \(7\)
\(=7×$1\)
\(=$7\)
- To calculate how much she spends, we will add the total cost of \(8\) notebooks and \(7\) sketchpads.
\(=$16+$7\)
\(=$23\)
- Thus, Amy spends \($23\).
Many times in everyday problems we need to deal with more than one operation. Only subtraction or multiplication does not help. We need to make use of the combination of operations in order to solve the problem.
For example:
- Roger wants to buy a computer that costs \($575\), including tax. He has been saving \($20\) each week for the past \(12\) weeks. How much more money does Roger need to purchase the computer?
- In the given example, each week Roger saved \($20\). He has been saving for the past \(12\) weeks. To calculate total amount of money he saved in \(12\) weeks, we will multiply \(20\) by \(12\).
\(20×12\)
\(=$240\)
He saved \($240\) in \(12\) weeks.
- To calculate how much more money he needs, we will subtract the money he saved from the total cost of the computer.
\(575-240\)
\(=$335\)
Thus, Roger needs \($335\) more to purchase the computer.
Many times in everyday problems we need to deal with more than one operation. Only addition or division does not help. We need to make use of a combination of operations in order to solve the problem.
For example:
- Three friends are planning the college function. The music band will charge \($180\). The food will cost \($300\) and \($110\) will be needed for decoration. \(295\) students have signed up for the dance. Out of the following amounts, how much money can they charge from each of the students to cover all the expenses?
- In the given example, to calculate total charges for college function, we will add the charges of band, food and decoration.
\($180+$300+$110\) \(=$590\)
Total expenditure on the college function is \($590\).
To calculate how much money can they charge from each student, we will divide the expenditure by the total number of students,
\($590\div$295\)\(=$2\)
They will charge \($2\) from each of the students.
Many times in everyday problems we need to deal with more than one operations. Only subtraction or only division does not help. We need to make use of a combination of operations in order to solve the problem.
For example:
- Tim earns \($1000\) in a month. He paid \($100\) for charity on Christmas eve. If he divided the remaining amount evenly among his three sisters, then how much money does each sister get?
- In the given example, Tim earns \($1000\) in a month and he paid \($100\) for charity. To calculate total amount of money left after paying for charity, we will subtract the money paid for charity from \($1000\).
\($1000-$100=$900\)
The remaining amount is \($900\). Thus, to calculate the amount that each sister gets, we need to divide the remaining amount by \(3.\)
\($900\div$3=$300\)
Tim gives \($300\) to each sister.
Many times in everyday problems we need to deal with more than one operation. Only multiplication or only division does not help, we need to make use of a combination of operations in order to solve the problem.
For example:
- Carl bought \(5\) rolls of tape to seal boxes. Each roll contains \(30\) meter of tape. He uses \(2\) meter of this tape to seal each box. What is the total number of boxes Carl can seal with these \(5\) rolls of tape?
- In the given example, Carl bought \(5\) rolls of tape and each roll is of \(30\) meter. To calculate total meter of \(5\) rolls of tape, we will multiply \(5\) rolls of tape by \(30\).
\(5×30\)
\(=150\;\text{meter}\)
- Carl has \(150\) meter of tape. He uses \(2\) meter to seal each box. To calculate the total number of boxes that can be sealed with \(150\) meter, we will divide \(150\) meter by \(2\) meter.
\(150\div2\)
\(=75\)
- Carl can seal \(75\) boxes with these \(5\) rolls of tape.