Integers & Negatives
Operations with negative numbers and integer properties
Generate Unlimited Practice Questions
Sign up for free and get 50 practice questions to start your prep.
Start Free PracticeLearn This Topic
Have you ever owed your friend money for a slice of pizza? Or played a video game where your score dropped below zero? Welcome to the wild world of negative numbers! ๐๐ฎ Integers are just whole numbers (no fractions or decimals allowed), but they have a secret alter ego: negatives. Think of a number line like a giant tug-of-war. Zero is the referee standing right in the middle. Positive numbers pull to the right, and negative numbers pull to the left. If you have 5 dollars in your piggy bank and want to buy a cool toy for 8 dollars, you don't just have zero dollarsโyou actually owe 3 dollars. In math language, we write that as . ๐ฆ On the SSAT, test-makers love to see how well you can juggle these positive and negative numbers. Adding a negative is just like taking away points in a video game. But subtracting a negative? Thatโs like a referee taking away a penaltyโit actually gives you points back! ๐ So, whenever you see two minus signs right next to each other, simply smash them together to make a giant plus sign. Master these simple rules, and you'll be an integer ninja ready to crush the math section!
Practice Questions
4 practice questions for SSAT Upper Level
Show Solution
- To evaluate the expression, follow the order of operations (PEMDAS/BODMAS):
- 1. Parentheses/Exponents:
โข (negative base raised to an odd power remains negative)
โข (negative base raised to an even power becomes positive)
- 2. Absolute Value:
โข (Subtracting a negative is equivalent to adding a positive. The absolute value of -6 is 6.)
- 3. Multiplication:
โข
- 4. Rewrite the expression with the calculated values:
โข The expression becomes
- 5. Addition/Subtraction (from left to right):
โข
โข
The final value of the expression is -47.
Show Solution
- Let's represent depths below sea level as negative numbers and ascents/descents as changes to this number.
- 1. Starting depth: 250 feet below sea level is feet.
- 2. Descends 120 feet: This means subtracting 120 from the current depth.
โข feet.
- 3. Ascends 80 feet: This means adding 80 to the current depth.
โข feet.
- 4. Descends another 170 feet: This means subtracting 170 from the current depth.
โข feet.
The final depth of the submarine is feet, which means 460 feet below sea level.
Show Solution
- Let's analyze the given conditions:
- 1. : This condition tells us that the product of and is negative. For a product of two non-zero numbers to be negative, one number must be positive and the other must be negative. So, and have opposite signs.
- 2. : This condition can be rewritten by adding to both sides as . This means is greater than .
Now, let's combine these two pieces of information:
โข Case 1: is positive and is negative.
โข If is positive (e.g., ) and is negative (e.g., ), then , which is less than 0. This satisfies the first condition.
โข Also, , which is greater than 0. This satisfies the second condition.
โข This case (a > 0 and b < 0) is consistent with both conditions.
โข Case 2: is negative and is positive.
โข If is negative (e.g., ) and is positive (e.g., ), then , which is less than 0. This satisfies the first condition.
โข However, , which is NOT greater than 0. This violates the second condition.
Since only Case 1 is consistent with both given conditions, it must be true that is positive and is negative.
Let's check the choices:
โข A) and : This contradicts our finding.
โข B) and : This matches our finding.
โข C) : This is not necessarily true (e.g., gives ).
โข D) : This is not necessarily true (e.g., means and , so ).
โข E) is an even integer: While is negative, it could be odd if both and are odd (e.g., , then , which is odd). So, this is not necessarily true.
Therefore, the statement that must be true is and .
Show Solution
- To find the average of a set of numbers, you sum the numbers and then divide by the count of the numbers. We are given the average and three of the four temperatures.
- 1. Set up the average formula:
- 2. Plug in the given values:
So,
- 3. Simplify the sum of known temperatures:
- 4. Rewrite the equation:
- 5. Solve for :
โข Multiply both sides by 4:
โข Add 5 to both sides:
Therefore, the temperature on the fourth day was .
Tips & Strategies
- Draw a quick number line on your scratch paper! It helps you physically count hops left and right so you don't get your positive and negative directions mixed up.
- Think of money! If a problem has lots of plus and minus signs, pretend you are earning and spending dollars. It makes the math feel much more real and easier to solve.
Common Mistakes
- Watch out for the 'double minus' trap! When you see , don't subtract. Taking away a negative penalty is a good thing, so it becomes a plus: .
- Don't confuse the rules for adding and multiplying! Adding two negatives makes a bigger negative (), but multiplying two negatives makes a positive ().
Frequently Asked Questions
Do I need to memorize the rules for negative numbers for the SSAT?
Yes! Knowing that 'a negative times a negative is a positive' will save you tons of time. You will see these concepts all over the test.
What exactly is an integer? Are fractions integers?
Integers are only whole numbers and their negatives (like , , and ). Fractions like and decimals are NOT integers!
Is zero positive or negative?
Zero is the referee of the number lineโit is neither positive nor negative! It's just a neutral integer.
How many negative number questions are on the SSAT?
You'll see them everywhere! They don't just appear in basic arithmetic; they pop up in algebra and word problems too, making them super important to master.