We can write a number as a sum of its parts. 600 + 40 + 9 is the expanded form of 649. Putting the parts back together gives the number in standard form.
To find the value of a digit, look at its place. In 649, the 4 is in the tens place, so its value is 40, not 4. When a part is missing, use a zero: 700 + 5 is 705.
Worked example
Write 300 + 20 + 7 as a number.
- 300 gives 3 hundreds, 20 gives 2 tens and 7 gives 7 ones.
- Write the digits in order: hundreds, tens, ones.
Answer:327
Key words
- expanded form
- a number written as the sum of its parts
- standard form
- a number written with digits, like 327
- value
- how much a digit is worth
Practise this
New questions every time.
Common Core-referenced: 2.NBT.A.3