Grade 6 math notes

Place Value System 

• Indian System: Ones, Tens, Hundreds, Thousands, Ten Thousands, Lakhs, Ten Lakhs, 

Crores 

• International System: Ones, Tens, Hundreds, Thousands, Ten Thousands, Hundred 

Thousands, Millions 

Example: 5,43,21,678 (Indian) = 54,321,678 (International) = Fifty-four million three hundred 

twenty-one thousand six hundred seventy-eight 

Comparison and Estimation 

• Greater Than: a > b 

• Less Than: a < b 

• Equal To: a = b 

• Rounding off to nearest 10: Round 5 or more up, less than 5 down 

Example: 847 rounded to nearest 10 = 850; 843 rounded to nearest 10 = 840 

Example: Estimate 487 + 321 ≈ 490 + 320 = 810 (actual = 808) 

Roman Numerals 

• I=1, V=5, X=10, L=50, C=100, D=500, M=1000 

Example: XIV = 14, XLII = 42, XCIX = 99, MMXXIV = 2024