Tuesday August 9, 2011 Hubbs Center - Math 2 Agenda and Objectives
Today’s Objectives... We will review and discuss multiplying decimals, including the HW: 91 and 79. We will discuss and practice rounding decimals, HW: 92 and 83.
Review:Multiplying Decimals Steps: Ignore the decimal points and multiply as if the numbers were whole numbers. Count up the TOTAL number of decimal places, and that’s how many are in your answer. Add the decimal point to your answer. Video:http://www.mathplayground.com/howto_multiplyd ecimals.html Multiplying Decimals Online Game:http://cemc2.math.uwaterloo.ca/mathfrog/english/kidz/decM ulti6.shtml
Rounding Decimals Activity: Rounding Practice Rules for Rounding Decimals:1. Find the place value you want (the "rounding digit") and look at the digit just to the right of it.2. If that digit is less than 5, do not change the rounding digit but drop all digits to the right of it.3. If that digit is greater than or equal to five, add one to the rounding digit and drop all digits to the right of it. http://www.math.com/school/subject1/lessons/S1U1L3GL.htmlExample: Round 46.327 to the nearest hundredth. More than 5, so the 2 becomes a 3.46.327 --> 46.33
Rounding Decimals Example: Round 2.84 to the nearest tenth. 2.84 Less than 5, so the 8 stays the same. --> 2.8 Round 2.84 to the nearest whole number. 2.8 More than 5, so the 2 becomes a 3.. --> 3http://www.mathsisfun.com/rounding-numbers.html
Rounding Decimals Round 2.84 to the nearest whole number and 0.72 to the nearest tenth. 2.84is more than 5, so the 2 becomes a 3. 8 --> 3 2 is less than 5, so the 7 stays the same. 0.72 -->0.7 Multiply the rounded numbers: 3 x 0.7