Solving Decimal Equations by x / ÷ Lesson 3-6

Basic Decimal Knowledge Decimal represented by . “Decimal places”  the digits that come AFTER the decimal To x / ÷ decimals  DO NOT line up decimals When a decimal is “out of sight”  only add one when dividing (“on the right”) When multiplying decimals  total decimal places in problem = total decimal places in answer! When dividing BY decimals  move bottom decimal to end of # = move top decimal same direction/same # of moves

Solving Decimal Equations by x / ÷ Example: = -9n *divide into each digit AFTER decimal 9.09 = n

Solving Decimal Equations by x / ÷ Example: 0.9r= *move bottom decimal = move top decimal r = -6

Solving Decimal Equations by x / ÷ Example: m = (-7) m = (-7) -7 *total decimal places in problem = total decimal places in answer m = 87.5

Solving Decimal Equations by +/- Example: s = (0.2) s = 5.3 (0.2) 0.2 *total decimal places in problem = total decimal places in answer s = 1.06

Practice Solve: a) -80 = t 4.5 b) 0.8x = -1.6 c) r = d) -2.4 = -1.2c

Homework p #20-24, 29, 39-41