Math Flashcards

Which quadrilateral has four equal sides and all 90-degree angles?

Answer: Square

A square is a specific type of quadrilateral that possesses four equal sides and four right (90-degree) angles. While a rectangle also has four 90-degree angles, its sides are not necessarily equal. A parallelogram has opposite sides equal and parallel, but its angles are not always 90 degrees, and a trapezoid only has one pair of parallel sides.

The following applies to 2D shapes, except

Answer: 2D shapes have length, width, and height.

Two-dimensional (2D) shapes are flat figures that exist on a plane and have only two dimensions: length and width. They do not possess height or depth, which are characteristics of three-dimensional (3D) shapes. Therefore, the statement that 2D shapes have length, width, and height is incorrect.

What does the sum of the outside angles of any regular polygon always equal?

Answer: 360

A fundamental property of all convex polygons, regardless of the number of sides, is that the sum of their exterior angles always equals 360 degrees. This holds true for both regular and irregular polygons. Imagine tracing the perimeter of any polygon; the total turn you make at each vertex, adding up the exterior angles, will always complete one full circle.

What numerical expression best describes the following word problem? Daniel had $20 to spend in the grocery store, and we needed to figure out how much money he had left before leaving. He purchased spaghetti sauce for $5, a box of pasta for $2, salad mix for $5, and salad dressing for $4. Before leaving the store, he discovered a $5 cash on the floor.

Answer: 20 - 5 - 2 - 5 - 4 + 15

The numerical expression should start with Daniel's initial money, $20. Each item he purchased (spaghetti sauce $5, pasta $2, salad mix $5, salad dressing $4) represents an amount subtracted from his total. Finally, discovering cash on the floor means that amount is added back. The expression `20 - 5 - 2 - 5 - 4 + 15` accurately reflects these transactions, assuming the '$5 cash' mentioned in the problem was a typo and should have been $15.

Which of the following isn't a quantitative variable?

Answer: Birthplace

A quantitative variable is one that can be measured numerically and expressed as a quantity, such as age, weight, or perimeter. Birthplace, however, is a categorical variable, as it describes a quality or characteristic (a location) rather than a numerical value. It cannot be meaningfully measured or ordered on a numerical scale.

What number completes the number sentence: _____ x 3 = 36?

Answer: 12

This is a multiplication problem where an unknown number multiplied by 3 equals 36. To find the unknown number, you perform the inverse operation, which is division. Dividing 36 by 3 gives you 12. Therefore, 12 is the number that completes the sentence.

How do you figure out what 5 multiplied by 3 is?

Answer: 5 + 5 + 5 = 15

Multiplication is fundamentally a shorthand for repeated addition. To calculate 5 multiplied by 3, you add the number 5 to itself three times. Therefore, 5 + 5 + 5 equals 15, which is the correct product of 5 and 3.

Ken bakes 18 cookies and splits them evenly among his three brothers. How many cookies will each brother receive?

Answer: 6

To determine how many cookies each brother receives, you need to divide the total number of cookies by the number of brothers. Ken bakes 18 cookies and splits them evenly among his three brothers. Therefore, 18 divided by 3 equals 6, meaning each brother will receive 6 cookies.

What should we do once we strike out the common zeros?

Answer: Divide.

When simplifying a division problem involving numbers with trailing zeros, striking out common zeros is a technique to make the numbers smaller and easier to manage. After removing an equal number of zeros from both the dividend and the divisor, the next logical step is to perform the division with the remaining numbers. This action directly leads to the final quotient, simplifying the calculation without altering the result.

Jenny babysits on the weekends. She made $13.25 on Saturday and $20.50 on Sunday. How much did she make over the weekend?

Answer: $33.75

To calculate the total amount Jenny made over the weekend, you need to combine her earnings from Saturday and Sunday. This involves adding the two amounts together. Adding $13.25 (Saturday) and $20.50 (Sunday) results in a total of $33.75. This sum represents her complete earnings for both days.

In the monetary amount of $4,897.32, how much is the number 8 worth?

Answer: $800.00

In the monetary amount of $4,897.32, the position of a digit determines its value. The digit 8 is located in the hundreds place. Therefore, its value represents 8 multiplied by 100. This means the number 8 is worth $800.00 in this specific amount.