Name:______Period:______

Date: ______

Chapter 3 TEST REVIEW/NOTES

Place Values:

  • Memorize place values and review how to read numbers.

7 / 2 / 4, / 6 / 5 / 2, / 8 / 4 / 6 / . / 9 / 4 / 7 / 2 / 3 / 6
Hundred Millions / Ten Millions / Millions / Hundred Thousands / Ten Thousands / Thousands / Hundreds / Tens / Ones / Decimal Point -“And” / Tenths / Hundredths / Thousandths / Ten Thousandths / Hundred Thousandths / Millionths

Reading Numbers –

  • Pronounce the number in front of the decimal as a WHOLE number.
  • Pronounce the DECIMAL POINT as “AND”
  • AFTER the decimal point, ignore the decimal and read the number as a whole number, then say the PLACE VALUE where the last digit falls.

Ex: 472,193.982 – “Four hundred seventy-two thousand one hundred ninety-three AND nine hundred eighty two THOUSANDTHS”

ROUNDING (Lesson 3.2):

  • If the place value you are rounding to is followed by 5, 6, 7, 8, or 9, round the digit in the place value UP. “This is called Rounding up.”
  • All place values less than the place value you are rounding to turn to zeros! In other words, ALL PLACES VALUES TO THE RIGHT OF THE PLACE VALUE YOU ARE ROUNDING TO TURN TO ZERO’S.

Ex: 4.862 rounded to the nearest tenth is 4.9.

  • If the place value you are rounding to is followed by 0, 1, 2, 3, or 4, keep the digit in the place value the SAME. This is called “Rounding down.”
  • All place values less than the place value you are rounding to turn to zeros! In other words, ALL PLACES VALUES TO THE RIGHT OF THE PLACE VALUE YOU ARE ROUNDING TO TURN TO ZERO’S.

Ex: 4.862 rounded to the nearest hundredth is 4.86.

ADDING AND SUBTRACTING DECIMALS (Lesson 3.1):

  • Line up decimal point and place values.
  • Annex, or add zeros as need be.
  • Add/Subtract from right to left.

Ex: 82.9 – 2.38 = 192.32 – 3.28

Multiplying Decimals (Lesson 3.3-3.4):

  • You DO NOT need to line up decimals and place values when multiplying decimals!
  • Multiply factors as if they are whole numbers (ignore the decimals).
  • Count the number of place values of each of the factors (the numbers being multiplied).
  • Place the decimal point in your PRODUCT the same number of place values from the right as the SUM OF THE PLACE VALUES OF THE FACTORS!

Ex:

Dividing Decimals (Lesson 3.5-3.8)

  • Parts of a division problem:
  • Quotient – the answer
  • Dividend – number that is being divided
  • Divisor – the number you are dividing by
  • Long Division
  • Work from LEFT to RIGHT
  • Divide
  • Multiply
  • Subtract
  • Bring it Down
  • Repeat (if there is a remainder)
  • Annex a decimal and zeros if needed

to solve completely.

  • CHECK with the INVERSE OPERATION
  • Multiply the QUOTIENT by the DIVISOR and ADD the REMAINDER if there is one.

Example: Solve & CHECK.

  • Dividing a Decimal by WHOLE number
  • Divide just like you would with WHOLE numbers.
  • Place the decimal in the QUOTIENT directly above the decimal in the DIVIDEND.

Example:

  • Dividing a Decimal by a DECIMAL number
  • Multiply the DIVISOR and the DIVIDEND by a power of ten to make the DIVISOR a whole number!
  • Then divide just like you would with WHOLE numbers.
  • Place the decimal in the QUOTIENT directly above the decimal in the DIVIDEND.

Example: