sign operations | MathCelebrity Forum

# sign operations

1. ### Electrons have a charge of -1. Protons have a charge of 1. The total charge of an atom is the sum of

Electrons have a charge of -1. Protons have a charge of 1. The total charge of an atom is the sum of its electron charges and proton charges. Find the total charge of an atom with 24 protons and 32 electrons We use sign operations to get: +24 - 32 = -8
2. ### A submarine hovers at 240 meters below sea level. If it descends 160 meters and then ascends 390 met

A submarine hovers at 240 meters below sea level. If it descends 160 meters and then ascends 390 meters, what is its new position? 240 meters below sea level means a negative number, so we start with: -240 Descending 160 meters means our depth decreases, so we subtract: -240 - 160 = -400...
3. ### At midnight in Winnipeg, the temperature was −23°C. During the next 24 hours, the temperature rose 1

At midnight in Winnipeg, the temperature was −23°C. During the next 24 hours, the temperature rose 12°C, then dropped 8°C. What was the final temperature? We start with −23°C Temperatures rising 12°C mean we add: -23 + 12 = -11 Temperatures dropping 8°C mean we subtract: -11 - 8 = -19°C
4. ### The negative of the sum of C and D is equal to the difference of the negative of C and D

The negative of the sum of C and D is equal to the difference of the negative of C and D The negative of the sum of C and D means -1 times the sum of C and D -(C + D) Distribute the negative sign: -C - D the difference of the negative of C and D means we subtract D from negative C -C - D So...
5. ### At midnight, the temperature was -15 degrees Fahrenheit. By the next morning, the temperature had go

At midnight, the temperature was -15 degrees Fahrenheit. By the next morning, the temperature had gone up to 20 degrees. What was the temperature then? The student meant to say gone up 20 degrees. We start with -15. We add 20 -15 + 20 = 5
6. ### The temperature in Chicago was five (5) degrees Celsius in the morning and is expected to drop by as

The temperature in Chicago was five (5) degrees Celsius in the morning and is expected to drop by as much as 12 degrees during the day. What is the lowest temperature in Chicago for the day? We start with 5 celsius A drop in temperature means we subtract 5 - 12 = -7 or 7 degrees below zero
7. ### Louis kept money through a hole inn his pocket. He started with 35 cents, lost 20 cents , put in 75

Louis kept money through a hole inn his pocket. He started with 35 cents, lost 20 cents , put in 75 cents , spent 43 cents, lost 16 cents again, and then put in 14 cents. How much change should there be in his pocket? The phrase put in mean we add money to the total The phrases spent or lost...
8. ### Steve woke up and it was -12 Fahrenheit outside the weatherman said it was supposed to warm up to 20

Steve woke up and it was -12 Fahrenheit outside the weatherman said it was supposed to warm up to 20 degrees. how many degrees will the temperature increase We start with a temperature of -12F Warming up means we add degrees to the original temperature. -12 + 20 = +8F
9. ### Karleys bank account was negative \$12.14. she then deposited \$21.63. What was her account balance

Karleys bank account was negative \$12.14. she then deposited \$21.63. What was her account balance negative 12.14 can be written as -12.14 She then deposited 21.63 which means we add 21.63 to her bank account balance: +21.63 Final account balance is: -12.14 + 21.63 = \$9.49
10. ### Storm Center 7 was tracking a cold front approaching Cedarburg. Before it rolled in, the temperature

Storm Center 7 was tracking a cold front approaching Cedarburg. Before it rolled in, the temperature was – 7°F. Then, the temperature decreased by 9°F. What was the temperature after the cold front rolled in? Using signed integers, we start with 7 below or -7 -7 The temperature decreased by 9...
11. ### Jina's test score average decreased by 10 points this semester. Write a signed number to represent t

Jina's test score average decreased by 10 points this semester. Write a signed number to represent this change in average. Let A be the original average. The new average is: A + (-10)
12. ### A man is swimming at 10 feet below sea level. Then he descends 1 feet and then ascends 5 feet. What

A man is swimming at 10 feet below sea level. Then he descends 1 feet and then ascends 5 feet. What is the man's new location? 10 feet below sea level is written as -10 He descends 1 foot. Since descending is negative depth, we have: -10 - 1 = -11 Then he ascends 5 feet, so we add: -11 + 5 =...
13. ### A patient’s temperature was 103°. The temperature then fell by 4° and later rose by 2°. What was the

A patient’s temperature was 103°. The temperature then fell by 4° and later rose by 2°. What was the patient’s final temperature Start with 103 Fell by 4 means we subtract 4: 103 - 4 = 99 Rose by 2 means we add 2L 99 + 2 = 101
14. ### what integer is used for losing 10 yards

what integer is used for losing 10 yards A loss means a negative, so a 10 yard loss is written as -10
15. ### Death Valley in California is 282 feet below sea level. Grant Hill Park, which is right across from

Death Valley in California is 282 feet below sea level. Grant Hill Park, which is right across from our school is 167 feet above sea level. How many feet higher is Grant Hill compared to Death Valley? Below sea level is written as a negative, so we have: Difference in feet = 282 - (-167)...
16. ### An 8 yard gain and a 3 yard loss results in what kind of gain or loss?

An 8 yard gain and a 3 yard loss results in what kind of gain or loss? Start with 0 yards Gains means we add, so we have 0 + 8 = 8 Losses mean we subtract, so we have 8 - 3 = 5 The overall result is a 5 yard gain
17. ### Jose earned 60 points on a game show. In the next round he lost 64 points then gained 12 points and

Jose earned 60 points on a game show. In the next round he lost 64 points then gained 12 points and at last lost 28 points. What was his score at the end of the show? Start with 60 points: 60 lose 64 means we subtract 64 from our points 60 - 64 = -4 Gained 12 means we add 12 to our points: -4...
18. ### A submarine sits at –300 meters in relation to sea level. Then it descends 115 meters. What is its n

A submarine sits at –300 meters in relation to sea level. Then it descends 115 meters. What is its new position in relation to sea level? Descending means we go down in sea level, so we subtract: -300 - 115 = -415 or 415 meters below sea level
19. ### the elevation of this lake is -513 if you are standing 442 above the lake what is your elevation

the elevation of this lake is -513 if you are standing 442 above the lake what is your elevation Standing above means we add: -513 + 442 = -71
20. ### If the temperature during the day is 6° and the temperature drops 15° after sunset, what is the temp

If the temperature during the day is 6° and the temperature drops 15° after sunset, what is the temperature at night? A drop in temperature means we subtract, so we have: 6 - 15 = -9 or 9 below zero