Welcome to fifth grade algebra! Today we'll learn about variables. A variable is a letter that represents an unknown number. Think of variables as mystery boxes that hold secret numbers. Common variables include x, y, z, and n for number.
Now let's learn to write expressions by translating words into math. When we say 'five more than a number', we write n plus five. 'Three times a number' becomes three times n. 'A number minus seven' is written as x minus seven. We're converting everyday language into mathematical expressions.
Now let's solve simple equations. An equation shows that two expressions are equal. For example, x plus three equals eight. We ask: what number plus three equals eight? By thinking through this, we find that five plus three equals eight, so x equals five. We can check our answer: five plus three does equal eight.
Let's explore patterns and rules. Look at this sequence: two, five, eight, eleven, fourteen. Can you see the pattern? We start with two and add three each time. The rule is: start with two, then add three repeatedly. We can write a formula: n equals three t minus one, where t is the position. Using this pattern, the next number would be fourteen plus three, which equals seventeen.
To summarize what we've learned about fifth grade algebra: Variables are letters that represent unknown numbers. We can translate word problems into mathematical expressions. Equations show that two expressions are equal. Patterns help us find rules and predict what comes next. The order of operations guides how we solve mathematical problems step by step.