Hundreds, Tens, and Ones: Numbers Up to 1,000

Imagine you have a big jar of marbles. You count 3 full bags of 100, 4 sticks of 10, and 7 loose ones. How many marbles do you think that is altogether? Have a guess before we begin — we will check your answer by the end of the lesson!

Every number is built from digits — the symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. In a number, each digit sits in a special position called its place. The place tells you what that digit is worth. For numbers up to 1,000, there are three important places: • Hundreds (H) — the leftmost place. • Tens (T) — the middle place. • Ones (O) — the rightmost place. Take the number 347. The digit 3 is in the hundreds place, so it is worth 300. The digit 4 is in the tens place, so it is worth 40. The digit 7 is in the ones place, so it is worth 7. Together: 300 + 40 + 7 = 347. This is called expanding the number — breaking it into the value of each part. Now go back to the marble jar. You had 3 hundreds, 4 tens, and 7 ones. That is 300 + 40 + 7 = 347 marbles. Did you guess correctly? Remember: the position of a digit changes its value completely. The digit 5 in 500 is worth 500. The same digit 5 in 50 is only worth 50. The same digit 5 in 5 is only worth 5.