How to multiply and divide decimals - HSPT Math

When multiplying decimals you ignore the decimals and multiply the two numbers like you would normally.

Then count the total number of decimal places to the right of the decimal of the original numbers.

Move the decimal from the whole number answer you just received to the left the same number of times as the total decimal places to the right of the numbers before you multiplied them.

Therefore the answer is

To solve:

First, find what is 20% of 55 by multiplying:

Then, subtract 20% (11) from the original price:

The final sale price will be $44.00.

To solve:

First find the corresponding percentage of each multiple choice answer,

a)

b)

c)

d)

Then, compare the amounts and select which amount is the largest:

b) 60

Examine the divisor 0.004. To make this a whole number, the decimal point needs to be moved three places right. Do this to both 0.004 and 320, adding an implied decimal point after the latter first:

Now perform this division:

First, multiply, ignoring the decimal points:

Put a decimal point after the number:

Since there were five digits total (one per factor) left of the decimal points, move the decimal point in the product left five places, inserting zeroes as needed:

The fraction has its last nonzero digit in the hundredths place, so write the number, without the decimal point, over 100. Then reduce.

To rewrite a very large number in scientific notation:

Write the number with the decimal point after it (it is implied to be at that location).

Move the decimal point left as many places as needed until it follows the first nonzero digit, which here is the four. Count the number of places it is moved - here it will be eleven places.

The number formed is , which will be placed in front; 11, the number of places counted, will be the exponent. The number, in scientific notation, will be .

is equal to , which is 20%.

Divide 8 by 15:

The 3 repeats, so the correct choice is .

Multiply the length of the race by the percentage accomplished by Andrew:

Answer: Andrew has completed 4000 meters of the race.

Find the amounts by multiplying each number to the percentage rate:

Compare the amounts to find the least. The answer is D.

Divide 84 by the entire amount of patches 120 to find the percentage completed.

The answer is Anita has completed 70% of the quilt.

Subtract the sale price from the original price:

Divide that amount by the original price to find the percentage of the sale.

Answer: The flight was reduced by 15%.

Subtract to find the amount of balloons that popped.

Then, divide

The answer: 40% of the balloons popped.

First, multiply 120 by 0.20.

Subtract that amount from the original price:

Answer: The sneaker's sale price is $96.00

Divide the number of words completed by the number of words needed:

Answer: Carolina has completed 74% of the essay.

First, multiply:

Then, subtract that amount from the original price:

Answer: Jacob will pay $223.80 using his coupon.

Multiply:

Answer: Gavin will save $200.70 by using the coupon.

First, multiply:

Then, subtract that amount from the original price:

Answer: Lola will pay $186.00 for the set of dishes.