Math Concepts and Estimation Flashcards

Which of these decimals is the greatest?

Answer: 0.54

Comparing tenths digits: 0.54 has 5 in the tenths and 4 in the hundredths, making it larger than 0.504 (5 tenths, 0 hundredths, 4 thousandths).

A bag contains 5 red marbles, 3 blue marbles, and 2 green marbles. What is the probability of picking a blue marble at random?

Answer: 3/10

There are 3 blue marbles out of 10 total (5+3+2=10), so the probability is 3/10.

Which number sentence shows the distributive property?

Answer: 4 × (3 + 5) = (4 × 3) + (4 × 5)

The distributive property states that a × (b + c) = (a × b) + (a × c), which matches 4 × (3 + 5) = (4 × 3) + (4 × 5).

If x + 8 = 15, what is the value of x?

Answer: 7

Subtracting 8 from both sides: x = 15 − 8 = 7.

A train travels 240 miles in 4 hours. What is its average speed?

Answer: 60 mph

Speed = distance ÷ time = 240 ÷ 4 = 60 mph.

Which of the following is closest to 1,000?

Answer: 10 × 100

10 × 100 = 1,000 exactly, making it the closest to 1,000.

A bookshelf has 6 shelves, each holding 25 books. About how many books are on the shelf if it is 80% full?

Answer: 120

Total capacity = 6 × 25 = 150 books; 80% of 150 = 0.80 × 150 = 120 books.