2.c Decimals Flashcards
(25 cards)
What is the easiest way to multiply decimals?
1) Ignore the decimals
2) Treat the two numbers as whole numbers
3) Multiply the numbers
4) Count the number of decimal places to the right of the decimal points in the original numbers
5) Move your resulted numbers back correspondingly
15.534 x 2.8 =
43.4952
0.5 x 0.6 =
0.3
! Watch out !
If the product of the numbers ends with 0 (5 x 6 = 30), do NOT use the shortcut of counting decimal points!
In the form a ÷ b, “a” is called the _________
Dividend
In the form a ÷ b, “b” is called the _________
Divisor
How else can a ÷ b be expressed?
How do you divide two decimals?
1) Move the decimal point of the divisor to the right until it becomes a whole number
2) Move the decimal point of the Dividend by the same number of places as the divisor
3) Divide the numbers using long division, keep the decimal point in the same location as in the new dividend for the quotient
5.1 ÷ 0.25 =
1) 510 ÷ 25
2) Long divide!
= thats it!
What would this be called:
“ 0.001 “
One Thousandth
What would this be called:
“ 0.01 “
One Hundreth
What would this be called:
“ 0.1 “
One Tenth
What is 195 rounded up to the nearest ten?
195, given the last number is 5 we add 1 to the 9. Can’t do that as this would make 10.
Answer == 200.
How would you express x% as a fraction?
x% = x / 100
eg. 5% = 5 / 100
How would you express x% + y% as fractions?
x / 100 + y / 100 = x + y / 100
How can you convert a fraction to a percent?
Multiply the fraction by 100 and attach a %
What would 3/2 be expressed as a percentage?
3/2 x 100 = 3/2 x 100/1 = 300/2 = 150
150%
What is 0.004 as a %?
0.4%
How would you express 0.7% as a decimal?
0.007
What are the 3 types of decimals?
1) Terminating decimals
2) Repeating decimals
3) Non-terminating and non-repeating decimals
What is a “terminating decimal”?
decimal that terminates
eg. 3.4 or 0.12
What is a “repeating decimal”?
decimal that repeats a pattern
3.44444444…..
or
0.1212121212…..
What is a “non-terminating and non-repeating decimal”?
decimal that does not terminate, and that has no pattern to it
eg. 3.141587693…
How would you convert “0.679” into a fraction?
0.679
679 / 1000
What is a base fraction?
A base fraction is a fraction that has the numerator of 1.
