[scheduled:: 2025-01-17]

Decimals

Links and useful resources

• gr7's Prealgebra Course Outline START HERE<<<
• IXL Grade 7 index
• IXL Grade 8 index
• AoPS Alcumus
• Handwritten math converter
• IXL prealgebra practice index
• OpenSTAX Prealgebra-1 textbook

Lesson-specific resource links

• IXL Comparing decimals
• Basic operations with decimals

Concept summary and connections

• decimal representation
• percentages
• decimals as fractions
• fractions as decimals
• arithmetic with decimals
• rounding decimals
• comparing and ordering decimals

Worked examples

Homework Review

Inequalities gave some serious trouble, let's do some together:

1. assume $a>b>c>d$
   1. is $a+c>b+d$ ?
   2. is $a+d>b+c$ ?
   3. is $ac>bd$ ?
   4. is $ab>cd$ ?

Things to try:

• What if some or all of them are negative?
• Write variables as e.g. $a^{+}$ or $b^{-}$:
  • is $b^{+}+d^{+}>b+d$? both numbers on the left are greater, so the sum is greater
  • is $a+d>b+c$ ? Rewrite it as $b^{+}+c^{-}>b+c$ ? Could be either way, one number is bigger and the other is smaller.

Media resources

• Youtube search for "decimal representation"
• Youtube search for "percentages"
• Youtube search for "decimals as fractions"
• Youtube search for "fractions as decimals"
• Youtube search for "arithmetic with decimals"
• Youtube search for "rounding decimals"
• Youtube search for "comparing and ordering decimals"

Guided practice

• Compare 9.01 and 9.011
• Compare 0.015 and 0.02
• compare 100.010 to 101.101
• Round 107.6554 to the nearest hundredth
• Round 0.9991 to the nearest thousandth
• Round 0.9991 to the nearest hundredth
• Compute 9.822 + 102.099
• Compute 1.9-1.7882

Homework

• #hw (math-gr7) IN CLASS IXL Rounding Decimals 2025-01-17
• #hw (math-gr7) 6.1 Arithmetic with Decimals (p. 247) 2025-01-20 [score:: 15/19]