Number System
Lessons in this chapter
About Number System
Number System stops adding one column at a time and asks for the pattern itself: once a child sees that each place is ten times the one to its right, any number length follows.
Read and Write 5 Digit Numbers and Identify Place Values of Digits and Expanded Form of 5 and 6 Digit Numbers push past the thousands into ten-thousands and hundred-thousands. The naming is where kids slip, because 60,000 and 600,000 sound similar and look similar at a glance.
Expanded form is the check that place value is really understood. Writing 46,207 as 40,000 + 6,000 + 200 + 7 means a child has to account for the zero in the tens column, which is exactly the digit a shaky understanding drops.
Compare and Order Numbers up to 6 Digits applies the same left-to-right rule as every earlier grade. Round Multi-Digit Numbers generalises rounding to any place, so the same procedure now works to the nearest ten or to the nearest hundred thousand, which is the point: one rule, not six.
All four lessons here open as a 4th grade math worksheet inside the page. Read and Write 5 Digit Numbers, Compare and Order Numbers up to 6 Digits and Round Multi-Digit Numbers each set their own math problems, worked one at a time and marked as you go. They are free and there is nothing to set up first.
Frequently asked questions
It opens with Read and Write 5 Digit Numbers, then Identify Place Values of Digits and Expanded Form of 5 and 6 Digit Numbers pushes past the thousands into ten-thousands and hundred-thousands. Compare and Order Numbers up to 6 Digits applies the same left-to-right rule used in earlier grades, and Round Multi-Digit Numbers generalises rounding so one procedure works at any place. The chapter sits in the Common Core domain Number and Operations in Base Ten (4.NBT).
How to read and write numbers up to six digits, give each digit's place value, write them in expanded form, compare and order them, and round to any place.
Because it exposes the zeros. Writing 46,207 as 40,000 + 6,000 + 200 + 7 forces a child to account for the empty tens column, which is where errors hide.
Look at the digit immediately to the right of the place you are rounding to. 5 or more rounds up, less than 5 rounds down. The place changes; the rule does not.
They sound alike and look alike at a glance. Reading the comma grouping, and saying the place name out loud, is what separates them.
Each place is ten times the one to its right. Once that is clear, a child does not need to learn each new column separately.