AR · 8 cards

Decimals and Place Value flashcards

8 cards with the formulas, rules and traps from this lesson. Answer in your head, then flip to check.

Term · 1/8
What are the first three decimal places to the right of the point?
Tenths, hundredths and thousandths; each place is worth one tenth of the place to its left. In 36.582, the 8 stands for 8 hundredths, or 0.08.
Common trap · 2/8
Which is larger, 0.5 or 0.45?
0.5. Pad with zeros to the same length (0.50 versus 0.45) before comparing; a decimal with more digits is not automatically bigger.
Rule · 3/8
How do you round a decimal to a given place?
Check the digit just right of the target place: 5 or more raises the target digit by one, 4 or less leaves it. 7.364 becomes 7.4 to the tenth and 7.36 to the hundredth; 2.995 becomes 3.00.
Rule · 4/8
Where does the decimal point go in a product of decimals?
Multiply as whole numbers, then give the product as many decimal places as both factors have in total: $32 \times 45 = 1440$ , so $3.2 \times 0.45 = 1.44$ , and $0.3 \times 0.2 = 0.06$ .
Rule · 5/8
How do you divide by a decimal, as in $8.64 \div 0.4$ ?
Move the divisor's point right until it is a whole number and move the dividend's point the same number of places: $86.4 \div 4 = 21.6$ . Shifting only one of them changes the answer.
Rule · 6/8
What happens when you multiply or divide by 10, 100 or 1,000?
The decimal point shifts one place per zero, right when multiplying and left when dividing: $3.07 \times 1000 = 3070$ and $52.6 \div 100 = 0.526$ .
Fact · 7/8
Decimal forms of 1/8, 1/5, 3/4 and 7/8?
$\frac{1}{8} = 0.125$ , $\frac{1}{5} = 0.2$ , $\frac{3}{4} = 0.75$ , $\frac{7}{8} = 0.875$ . Any fraction converts by dividing the numerator by the denominator.
Rule · 8/8
How do you write 0.36 as a fraction?
Put the digits over the place value of the last digit, then simplify: $0.36 = \frac{36}{100} = \frac{9}{25}$ .

← Fractions and Mixed Numbers Percentages →