Number System for Class 6 — Free CBSE Worksheet PDF with Answers

Numbers are everywhere — the population of India, the distance to the Moon, the price of your favourite cricket bat. But can you read a 7-digit number without stumbling? Can you tell which is bigger: $59,73,482$ or $60,01,003$? Knowing Our Numbers is the first chapter in Class 6 CBSE maths because it builds the number sense you need for every topic that follows.

This chapter covers comparing and ordering large numbers up to 8 digits, the Indian and International place value systems, reading and writing numbers in words, rounding off and estimation, and Roman numerals. Mastering these now makes data handling, large-number arithmetic, and even algebra in later classes much smoother.

The worksheet contains 60 graded questions: 20 at Level 1 (place value, reading numbers, comparisons), 20 at Level 2 (estimation, rounding, word problems), and 20 at Level 3 (Indian-International conversions, multi-step problems, tricky comparisons).

The Indian system places commas after the hundreds digit, then every two digits going left: $1,23,45,678$ reads as one crore twenty-three lakh forty-five thousand six hundred seventy-eight. The places are ones, tens, hundreds, thousands, ten thousands, lakhs, ten lakhs, crores. The International system places commas every three digits: $12,345,678$ reads as twelve million three hundred forty-five thousand six hundred seventy-eight. The places are ones, thousands, millions, billions.

Both systems describe the same number, just grouped differently. $1,25,00,000$ in Indian is $12,500,000$ in International — both are twelve and a half million, or one crore twenty-five lakh. CBSE Class 6 expects you to be able to convert between the two, especially the placement of commas.

Estimation is finding an approximate answer quickly, useful when an exact answer is not needed or when checking whether an exact answer is reasonable. The standard NCERT method is to round each number to its largest place value, then perform the operation.

To estimate $4,836 + 7,245$, round each to the nearest thousand: $5,000 + 7,000 = 12,000$. To estimate $3,845 + 22,316$, round to the nearest thousand (the larger number's smaller place value): $4,000 + 22,000 = 26,000$. Rounding rules: look at the digit just after the place you are rounding to. If it is 5 or more, round up. If less than 5, round down.

Roman numerals use seven letters: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000. Numbers are formed by combining these. The key rules: V, L, and D are never repeated. I, X, and C can be repeated up to three times. Subtraction works only when a smaller numeral comes before a larger one — and only I before V or X, X before L or C, C before D or M.

Examples: IV = 4 (5 - 1), IX = 9 (10 - 1), XL = 40 (50 - 10), XC = 90 (100 - 10), CD = 400, CM = 900. So 1994 in Roman numerals is MCMXCIV. Class 6 students should be comfortable converting numbers up to 100 to and from Roman numerals.