Welcome to the Game World of Mathville!
In Mathville, numbers and operations are like superheroes. Each one has a special power. Let's meet the main heroes:
- \(+\) Add-Man
- \(\times\) Multi-Girl
Who's Stronger?
Whenever Add-Man and Multi-Girl go on a mission together, there's a rule:
Multi-Girl always goes first! (She's quicker and stronger in missions!)
If you see a mission like \(30 + 5 \times 4\), don't start with Add-Man. You must send Multi-Girl first!
First, Multi-Girl \((\times)\) steps in: \(5 \times 4 = 20\)
Second, Add-Man \((+)\) joins: \(30 + 20 = 50\)
So, the result of the mission is \(50\).
But Wait.. What if you send the wrong hero first?
Some kids might send Add-Man first and do:
\(30 + 5 = 35\), then \(35 \times 4 = 140\)
Oops! That messes up the mission. The answer is totally wrong!
How Do We Avoid Confusion?
We use something magical in Mathville: BRACKETS!
Brackets are the heroes. They tell exactly what to do in what order.
Expression: \(30 + (5 \times 4) = 30 + 20 = 50\)
Rules for doing complex expressions:
- Brackets are special. Always follow them first.
- And, then do the next operation
Terms in Expressions
Terms are parts of the expression separated by a ‘\(+\)’ sign.
Example:
In the expression \(10 + 7\), there are two terms present.
One is \(10\) and the other is \(7\).
What if there’s a minus sign?
Suppose the expression is \(30 - 8\).
Subtracting \(8\) from \(30\) is same as adding the opposite of \(8\).
So, \(30 - 8 = 30 + (-8)\).
Now, the terms are \(30\) and \(-8\).