Comparing and ordering

In your book, Maths Mela (Chapter 1), a student says 9,990 is greater than 49,014 because 9 is greater than 4. Is that right? No! Put both numbers in the place value chart. 49,014 has 4 ten thousands. 9,990 has no ten thousands at all: it is only a 4-digit number. So 49,014 is much bigger. On a number line, 9,990 sits just before 10,000, while 49,014 is near 50,000.

To compare two numbers, look at their places, starting with the biggest place. A 5-digit number is always bigger than a 4-digit number. If both have five digits, compare the ten thousands first; if those are the same, compare the thousands, then the hundreds, and so on. Ravi's car has been driven 56,987 km and Sheetal's car 67,543 km. 6 ten thousands is more than 5 ten thousands, so Sheetal's car has been driven more.

We can put numbers in increasing order (smallest first) or decreasing order (biggest first). The book lists prices of electric bikes. In increasing order they are ₹39,999, ₹49,900, ₹89,999, ₹90,000, ₹93,743, ₹94,983. Look at ₹89,999 and ₹90,000: 8 ten thousands is less than 9 ten thousands, so ₹89,999 comes first, even though it has so many 9s.

We can also find numbers that lie between two numbers. Between 23,568 and 24,234 are numbers like 23,600, 23,900, 24,000 and 24,100. The book asks for numbers between 42,750 and 53,500 whose ones, tens and hundreds are all 0. These are whole thousands: 43,000, 44,000, 45,000 and so on up to 53,000. 42,000 is too small (it is less than 42,750) and 54,000 is too big.