Math Rev Tom🤺

• Place value


  The value of a digit in a number based on its position
• Place value positions


  • Ones
  • Tenths
  • Hundredths
  • Thousandths
• The value of a digit in a decimal is determined by the place it occupies
• The first place to the right of the decimal point is the tenths place, the second place is the hundredths place, and the third place is the thousandths place
• Whole numbers have no decimal places
• Decimal numbers have a decimal point that separates the whole number part from the decimal part
• The place value chart shows the value of each place in a number
• Rates


  A comparison of two quantities
• Ways to express a rate

  • By phrase (e.g. 2 hearts and 1 diamond)
  • By colon (e.g. 2:1)
  • By fraction (e.g. 2/1)
• Percentage


  A special type of rate where the base is 100
• To calculate a percentage rate

  1. P = B

  2. R = P/B

  3. B = P/R
• 15 is 25% of 248
• Integers


  Whole numbers, both positive and negative
• Integers


  • -10,-9,-8,-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7,8,9,10
• Plane figures


  • Have 2 dimensions: length and width
• Solid figures


  • Have 3 dimensions: length, width and height
• Plane figures


  • Triangle
  • Quadrilateral
  • Pentagon
  • Octagon
• Algebraic expression


  A mathematical expression that combines numbers and one or more operations with variables
• Variable


  A letter or symbol that represents a number
• Constant


  A fixed value that does not change
• Operation symbols


  • +
  • -
  • x
  • ÷
  • =
• Formula


  An equation that shows the relationship between different measurements
• Formulas


  • Area of a square = A = s x s
  • Area of a rectangle = A = l x w
  • Area of a triangle = A = 1/2 b x h
  • Area of a circle = A = π r^2