Entering Pre-Algebra Quiz

Study Notes

Determine the number of tens in a number by dividing by 10. For example, in 317, the answer is 31 tens.
Rounding to the tens place involves looking at the unit digit; if it's 5 or more, round up, otherwise round down (e.g., 635 rounds to 640).
Expanded form expresses a number as a sum of its parts, such as 3,000 + 100 + 10 + 7 for 3, 017.
Basic arithmetic examples include addition (e.g., 2,431 + 186 = 2,617) and subtraction (e.g., 5,042 - 473 = 4,569).

Solve decimal addition problems like 3.26 + 9.42 to get 12.68, ensuring proper alignment of decimal points.
Similar addition with larger numbers: 6.176 + 42.08 results in 48.256.
With subtraction, calculate 14.06 - 8.200 to find 5.86.
Converting fractions to decimals and then to percents is essential, e.g., understanding that 0.5 equals 50%.

Simplifying expressions involves combining like terms and applying mathematical rules. For instance, −65 + 7 simplifies to −58.
Handling negative numbers is crucial, such as in 36 − (−6), which becomes 42.

Follow the order of operations (PEMDAS/BODMAS) for calculations.
Example: For 40 − 12 ÷ (2 + 3), first divide, then subtract to yield the final answer.
For expressions like (70 + 15) ÷ 5, add first, then divide for the solution.

Word problems require carefully reading to extract numbers and operations.
For example, Mina's coffee shop spending can be found by subtracting the remaining amount from the original total: $50.00 - $37.80 = $12.20.
In the gym scenario, calculate the number of used seats by applying the percentage: 80% of 100 seats equals 80 used seats.