SCIENTIFIC NOTATION FOR WRITING VERY BIG AND VERY SMALL NUMBERS

Easy to recognize because they are written as a power of ten M X 10 8 MANTISSA: ONLY SIG FIGS. EXPONENT + = large # - = small #

TO WRITE A NUMBER IN SCIENTIFIC NOTATION Find the sig. figs. Move decimal between the 1st and 2nd sig. fig. → MANTISSA # of spaces and direction moved → EXPONENT for the power of ten. left = positive right = negative

PROPER ONE DIGIT LEFTPROPER scientific notation form can only have ONE DIGIT to the LEFT of the decimal

PRACTICE PROBLEMS WRITE IN PROPER SCI. NOTATION FORM 1) mm 2) cg

ANSWERS 1) 4.05 X mm 2) 6.70 X cg

MATH WITH SCI. NOTATION (and SIG FIGS) MULTIPLICATION –M–MULTIPLY MANTISSAS –A–ADD EXPONENTS. Ex.: (2.5 X 10 3 )(6.4 X 10 2 ) WORK: (2.5 * 6.4) X = 16 X 10 5 must correct for improper form FINAL ANSWER: 1.6 X 10 6

Part of the work 2.5 X

DIVISION –D–DIVIDE MANTISSAS –S–SUBTRACT BOTTOM EXPONENT FROM TOP Ex.: 4.5 X / 3 X WORK: (4.5 / 3) X –(-2) = 1.5 x FINAL ANSWER: 2 x 10 14

Part of the work

ADDITION –M–MUST HAVE SAME EXPONENT. ACHIEVED BY MOVING DECIMAL PT. IN THE MANTISSA –A–ADD MANTISSAS AND CARRY OVER EXPONENT.

Ex.: (1.5 X 10 3 ) + (3 X 10 2 ) = ? WILL NOT MATTER WHICH EXPONENT YOU CHANGE; WILL CHANGE 2 TO A 3 MOVE DECIMAL ONE PLACE TO LEFT (positive move) NOW NUMBER BECOMES.3 X 10 3 WORK:(1.5 X 10 3 ) + (.3 X 10 3 ) = 1.8 X 10 3 FINAL ANSWER: 1.8 X 10 3

Part of the work X 10 3

SUBTRACTION –MUST HAVE SAME EXPONENT. ACHIEVED BY MOVING DECIMAL PT. IN THE MANTISSA –SUBTRACT MANTISSAS AND CARRY OVER EXPONENT.

Ex.: (2.1 X ) – (5 X ) = ? WILL CHANGE –3 TO A –2 MOVE DECIMAL TO LEFT ONE SPACE (positive move) NOW NUMBER BECOMES.21 X WORK:(.21 X ) – (5 X ) = X FINAL ANSWER: -5 X 10 -2

Part of the work OR X 10 -2

PRACTICE PROBLEMS COPY AND WORK. ANSWERS MUST BE IN SCI. NOTATION WITH CORRECT SIG FIGS. 1)(6.78 x ) + (3.345 x ) =? 2)(4.3 x ) – (7.89 x ) =? 3)(2.75 x )(3.3 x ) =? 4) (7.20 x 10 8 ) / (1.2 x )=?

ANSWERS 1) 7.11 x ) x ) 9.1 x ) 6.0 x 10 20