Aurora had $500 in her bank account at the beginning of September.
During the month she withdrew $415 and deposited $82?
Write and solve a directed number sentence to show the balance of Aurora's account at the end of the month? (2 marks)
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Aurora had $500 in her bank account at the beginning of September.
During the month she withdrew $415 and deposited $82?
Write and solve a directed number sentence to show the balance of Aurora's account at the end of the month? (2 marks)
` 500-415 + 82= +$167`
`text(Balance)\ = 500-415 + 82 = +167`
`:.\ text(Aurora’s balance)\ = +$167`
Two numbers added together equal `-1`.
The two numbers multiplied together equal `-56`.
What are the two numbers? (2 marks)
`7\ text(and)\-8`
`7 + -8` | `= -1` |
`7 xx -8` | `= -56` |
`:. 7\ text(and)\-8`
Two numbers added together equal `-`7.
The two numbers multiplied together equal 12.
What are the two numbers? (2 marks)
`-3 and -4`
`-3 + -4` | `= -7` |
`-3 xx -4` | `= 12` |
`:. −3 and −4`
An unknown number is added to `2`.
The result is multiplied by `4` to give an answer of `-4`.
Which of these is the unknown number?
`D`
`text(Option D:)`
`text(If unknown number) = -3`
` -3 + 2 = -1`
`-1 × 4 = -4\ text((correct))`
`=> D`
An unknown number is added to `5`.
The result is multiplied by `3` to give an answer of `-6`.
Which of these is the unknown number?
`A`
`text(Option A:)`
`text(If unknown number) = -7`
` -7 + 5 = -2`
`-2 × 3 = -6\ text((correct))`
`=> A`
Jennifer opened a bank account with $500. Each week for 4 weeks she withdrew $122 for rent. At the end of the month the bank deducted $15 in fees.
What was the balance of Jennifer's bank account at the end of the month? (2 marks)
`-$3`
`text(Balance)\ = 500-122 xx 4-15 = 500-488-15 = -3`
`:.\ text(Jennifer’s balance)\ = -$3`
Morgan had $134 in his bank account. At the end of March he paid $132 car insurance and the bank deducted $10 in fees.
What was the balance of Morgan's bank account at the beginning of April? (2 marks)
`-$8`
`text(Balance)\ = 134-132-10 = -8`
`:.\ text(Morgan’s balance)\ = -$8`
Jasper is a meteorologist working in Antartica. One of his jobs each week is to upload the daily maximum and minimum temperatures to the Base Camp website.
Jasper has partially completed his log book for this week but will need his additional notes to fill in the missing entries before he can upload them to the website.
Using Jasper's notes below, complete the missing log book entries. (4 marks)
Jasper's Additional Notes:
--- 8 WORK AREA LINES (style=lined) ---
TEMPERATURE LOG BOOK
\begin{array} {|l|c|c|}
\hline \textbf{Day} & \textbf{Minimum} & \textbf{Maximum} \\
\hline \text{Monday} & -10° & -1° \\
\hline \text{Tuesday} & -15° & \colorbox{lightblue}{−4°} \\
\hline \text{Wednesday} & -7° & -2° \\
\hline \text{Thursday} & \colorbox{lightblue}{−20°} & -8° \\
\hline \text{Friday} & -17° & -6° \\
\hline \text{Saturday} & \colorbox{lightblue}{−21°} & \colorbox{lightblue}{−2°} \\
\hline \text{Sunday} & -19° & -4° \\
\hline \end{array}
`1.\ text{Tuesday’s Maximum}\= -1-3 = -4`
`2.\ text{Thursday’s Minimum}\= -8-12 = -20`
`3.\ text{Saturday’s minimum}\= 3 xx -7 = -21`
`4.\ text{Saturday’s maximum}\= -4 ÷ 2 = -2`
TEMPERATURE LOG BOOK
\begin{array} {|l|c|c|}
\hline \textbf{Day} & \textbf{Minimum} & \textbf{Maximum} \\
\hline \text{Monday} & -10° & -1° \\
\hline \text{Tuesday} & -15° & \colorbox{lightblue}{−4°} \\
\hline \text{Wednesday} & -7° & -2° \\
\hline \text{Thursday} & \colorbox{lightblue}{−20°} & -8° \\
\hline \text{Friday} & -17° & -6° \\
\hline \text{Saturday} & \colorbox{lightblue}{−21°} & \colorbox{lightblue}{−2°} \\
\hline \text{Sunday} & -19° & -4° \\
\hline \end{array}
James runs a tyre fitting company.
At the beginning of February he took out a `$50\ 000` bank loan to expand his workshop.
In July James had flood damage in his workshop and added `$20\ 000` to his bank loan to pay for repairs.
By the end September he had made loan repayments totalling `$12\ 000` and had also deposited business profits of `$15\ 000` into his loan account.
Write a number sentence and use it to calculate how much James owed at the end of September. (3 marks)
`-$43\ 000`
`text(Amount of debt)` | `= -50\ 000-20\ 000+12\ 000+15\ 000` | |
`= -70\ 000+27\ 000 ` | ||
`= -43\ 000` |
`:.\ text(James’ debt at the end of September)\= -$43\ 000`
The daily high and low temperatures are measured in four ski resorts and recorded in the table below.
\begin{array} {|l|c|c|}
\hline \textbf{Ski Resort} & \textbf{Low} & \textbf{High} \\
\hline \text{Thredbo} & -1° & 6° \\
\hline \text{Charlotte's Pass} & -5° & 1° \\
\hline \text{Mount Hotham} & -2° & 3° \\
\hline \text{Perisher} & -4° & 4° \\
\hline \end{array}
--- 1 WORK AREA LINES (style=lined) ---
--- 1 WORK AREA LINES (style=lined) ---
a. `text(Mount Hotham)`
b. `text(Charlotte’s Pass)`
`text(Considering all options.)`
`text(Thredbo)` | `=6-(-1)` | `=7` |
`text(Charlotte’s Pass)` | `=1-(-5)` | `=6` |
`text(Mount Hotham)` | `=3-(-2)` | `=5` |
`text(Perisher)` | `=4-(-4)` | `=8` |
a. `text(Lowest Range)\ =\text(Mount Hotham)`
b. `text(Range of)\ 6 = text(Charlotte’s Pass)`
At midday the temperature is `-`3°C.
At 9pm the temperature is `-`12°C.
Which one of these calculations can be used to work out how many degrees warmer it is at midday than at 9 pm?
`B`
`text(Degrees warmer)` | `= -3-(-12)` | |
`=-3 + 12` |
`=> B`
At midday the temperature is 10°C.
At sunset the temperature is `-`6°C.
Which one of these calculations can be used to work out how many degrees warmer it is at midday than at sunset?
`C`
`text(Degrees warmer)` | `= 10-(-6)` | |
`=10+6` |
`=> C`
A buoy is in the ocean recording the height of waves passing by.
At sea level it measures 0 metres. It moves above and below sea level.
Which list gives four sea level recordings arranged in order from lowest to highest?
`D`
`=> D`
Rachel lives in Broome where the temperature on a particular day was 46°C.
Rachel's son lives in Winnipeg, Canada, and on the same day the temperature there was −16°C.
What was the temperature difference between the two towns on this day? (2 marks)
`62°text(C)`
`text(Temperature difference)` | `= 46-(-16)` |
`= 62°text(C)` |
Death Valley is the lowest point in the United States at `-`85 metres, which is below sea level.
King's Peak, also in the United States, is 4128 metres above sea level.
What is the difference, in metres, between Death Valley and King's Peak? (2 marks)
`4213\ text(metres)`
`text(Difference)` | `= 4128- (-85)` |
`= 4213\ text(metres)` |
Dilbert and Smacka were playing a game where they both started with zero points.
Dilbert's final score was 165 points and Smacka's final score was `-90`.
How many more points did Dilbert have than Smacka?
`D`
`text(Difference)` | `= 165 – (-90)` |
`= 255` |
`=> D`
Murray lives in Bundaberg, QLD, where the temperature on a particular day was 39°C.
Murray's son lives in Salt Lake City, USA, and on the same day the temperature there was `-`15°C.
What was the temperature difference between the two towns on this day? (2 marks)
`54°text(C)`
`text(Temperature difference)` | `= 39-(-15)` |
`= 54°text(C)` |
Manou placed an apple pie into his oven.
The 1st measurement of the apple pie's temperature was `-` 4°C.
Twenty minutes later, a second temperature reading was taken, which measured 21°C.
What was the change in temperature between the two measurements?
`C`
`text(Change in temperature)` | `=21-(-4)` |
`=25^@ text(C)` |
`:.\ text(An increase of 25°C.)`
`=> C`
The temperature at the summit of a large mountain is `-`6°C.
The temperature at the base of the mountain is 32°C warmer than at the summit.
What is the temperature at the base of the mountain? (2 marks)
`26^@text(C)`
`text(Temperature at the base of the mountain)`
`= -6 + 32`
`=26^@ text(C)`
Ivan left home and turned off the heater.
Before turning off the heater, the temperature in the room was 25°C.
When Ivan arrived home from work that night, the temperature in the room was `\-\`2°C.
What was the change in temperature in the room? Write your answer as a directed number. (2 marks)
--- 2 WORK AREA LINES (style=lined) ---
`-27text(°C)`
The Nevis Bungy in Queenstown is the highest bungee jump in New Zealand.
Jumpers launch downwards from a platform and take just 8.5 seconds to freefall 134 metres before the bungee cord retracts for the first time.
Express the length of the freefall as a directed number. Consider the platform to be at zero length. (1 mark)
`-134\ text(metres)`
`134\ text(metres below the platform) = -134\ text(metres)`
The average temperature at the Mount Everest base camp in Tibet is 17 degrees below zero.
Write this temperature as a directed number. (1 mark)
`-17 \ º`
`17 \ text(degrees below zero) = -17\ º`
Most commercial jet planes gain their cruising altitude of approximately 8000 metres within 10 minutes after take off.
Write this height as a directed number. (1 mark)
`\+\8000\ text(metres)`
`text(Ground level) = 0\ text(metres)`
`:. 8000\ text(metres cruising altitude) = \+\8000\ text(metres)`
The operating depth of most modern submarines is approximately 375 metres below sea level.
Write this depth as a directed number. (1 mark)
`-375\ text(metres)`
`text(Sea level) = 0\ text(metres)`
`:. 375\ text(metres below sea level) = -375\ text(metres)`
Pixie enters the elevator in her high rise office building on level 5.
She travels down in the lift for 8 floors.
By considering the floors above ground level to be positive and the floors below ground level to be negative, write and solve a number sentence that gives Pixie's position in the building when she gets out of the elevator. (2 marks)
--- 4 WORK AREA LINES (style=lined) ---
`5 \-\8 = \-\3`
`text(Pixie enters at level 5 and descends 8 floors, therefore the number sentence is:`
`5 \-\8= \-\3`
Jerome is on holidays in Thredbo. His family is hoping for a good covering of snow as they are having snowboarding lessons.
Which of the following outside temperatures would produce the snow they need?
`D`
`text(The temperature must be below 0º C for snow to fall.)`
`text(Therefore, the outside temperature would need to be −15ºC.)`
`=> D`