ffirs.indd

(Brent) #1

227





    • = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( )
      % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9
      ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8
      9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7
      8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6
      7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5
      6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3
      S SQUARING NUMBERS QUARING NUMBERS
      EENDING IN 5NDING IN 5
      When you multiply a number by itself (for example, 3 × 3, or 5 × 5,
      or 17 × 17), you are squaring it. Seventeen squared (or 17 × 17) is
      written as: 17^2. Th e small 2 written after the 17 tells you how many
      seventeens you are multiplying. If you wrote 17^3 it would mean
      three seventeens multiplied together, or 17 × 17 × 17.
      Now, to square any number ending in 5, you simply ignore the 5 on
      the end and take the number written in front. So, if we square 75
      (75 × 75), we ignore the 5 and take the number in front, which is 7.
      Add 1 to the 7 to get 8. Now multiply 7 and 8 together.
      7 × 8 = 56
      Th at is the fi rst part of the answer.
      For the last part you just square 5.
      5 × 5 = 25
      Th e 25 is always the last part of the answer. Th e answer is 5,625.
      AAppendix Jppendix J
      bbapp10.indd 227app 10 .indd 227 1 1/5/07 11:38:59 AM/ 5 / 07 11 : 38 : 59 AM



Free download pdf