#Integers negative and positive rules how to#

Those answers are dependant upon the original values. Note the second and third rows of the body of the table. If there is more debt than income the answer will be negative, like example 3.īelow is a table to help condense the rules for addition. If there is more income than debt the answer will be positive, like example 2. Similar to our temperature battle between warm temperatures and cold temperatures, adding positive and negative numbers is like comparing income to debt. In fact, accountants would call it 'falling deeper in debt.' When adding two debts, like example 4 above, the answer has to be another debt.

When adding two incomes, like example 1 above, the answer has to be a bigger income and the result is a positive number. The positive numbers represent income while the negative numbers represent debt. It can be helpful to think of money when doing integer addition. That will explain why the answer is negative. In example 3 there was more negative temperature than positive. When we added 8 and -2 in example 2, there was more positive temperature than negative temperature which would explain the result - positive 6. Adding two negative temperatures will result in a negative temperature, similar to example 4 above.Įxamples 2 and 3 can be understood in a different way by imagining a battle between two temperatures. Negative numbers make the temperature indicator fall.Īdding two positive temperatures will result in a positive temperature, similar to example 1 above. Positive numbers make the temperature indicator rise. The numbers can be thought of as temperature changes. The temperature model for adding integers is exactly the same as the movement model because most thermometers are really number lines that stand upright. Ideo: Add & Subtract Positive & Negative Numbers with Number Lines

#Integers negative and positive rules how to#

Here is a video that explains how to use a number line to add and subtract numbers. Since we are a total of eleven units left of zero, the answer is -11. If asked to add -6 and -5, first move six units to the left of zero. Since we land up nine units to the left of zero, the answer is -9. If asked to add -13 and 4, we start by moving thirteen units to the left of zero. Since our last position is six units to the right of zero, the answer is 6. Then we would move two units left from there because negative numbers make us move to the left side of the number line. If asked to add 8 and -2, we would start by moving eight units to the right of zero. Since we landed up seven units to the right of zero as a result of these movements, the answer must be 7. Then we would move three units to the right. If asked to add 4 and 3, we would start by moving to the number 4 on the number line - exactly four units to the right of zero. In order to add positive and negative integers, we will imagine that we are moving along a number Positive numbers extend to the right of zero and negative numbers extend to the left of zero. Traditionally, zero is placed in the center. You are probably familiar with a number line (see below). Lastly, we will take a look at the rules for addition. We can use movement, temperature and money. There are three appealing ways to understand how to add integers.