T​he second poster outlines the steps to rounding numbers, with an example included. 

You may also be interested in this fun ROUNDING Math Mystery: Case of The Robot Robbery.  Each grade version will engage and motivate your students to get lots of practice with rounding, as they must solve who the guilty robot is. 
3rd Grade Version - Rounding to the Nearest Ten and Hundred
4th Grade Version - Rounding Whole Numbers up to Millions
​5th Grade Version - Rounding Decimals

Counting & Ordering Numbers 1-20 Activity
For this simple activity, I labeled the numbers 1-20 on the individual Lego blocks.  On the opposite side of each block, I drew the amount of dots to represent the number (optional).

Once ready to begin the activity, spread the blocks out and jumble the numbers around as in the picture below. Keep all of the numerals facing upwards. Then, set the challenge to build a tower putting the numbers in the correct order from 1-20.

If stuck on the number, count the dots! 

I put Lego wheels on the base for my son since he loves trucks and cars, but any Lego base will do to help the tower from falling. He enjoyed driving his tower of 20 blocks around once he finished the task.

Differentiation option for older kids – Comparing and Ordering Larger Numbers
This activity can easily be adapted to suit older kids to work on comparing ordering larger numbers.
To do this, all I would do is label the blocks with the numbers appropriate to challenge the level of difficulty my students need.. Below is an example set for ordering 4-digit numbers.

​Then set the challenge to build a tower in ‘ascending’ order (from least to greatest). 

​Another great activity that can be used at home or in the classroom is this fun Math Mystery below, which focuses on Comparing and Ordering numbers, 'Case of The Outback Outlaw'. Kids will be practicing this important skill whilst also working on solving who stole the opals from the Coober Pedy mine in the Outback of Australia.
It's available in four different levels to choose difficulty from. Click on the grade level version below to find out what number range/s are explored in each..
​ 

​As the beginning of the year approaches (or has started for some), we look at lessons and units to help start off the year. One of the units is place value. Why? It helps students understand the meaning of the numbers they are writing and using. Without this foundational knowledge students can struggle in regrouping, understanding expanded notation, speaking, and writing the word form of standard numbers. Included below are some collected ideas and units to help strengthen students place value understanding.
 
Place Value Houses Project Idea –
​Mrs. Hansen’s Helpfuls
One strategy I use to help build the skills for a strong place value foundation is to create Place Value Houses. This project allows students to visually see how numbers are grouped into “threes” and allows students to practice number formation, speaking, and writing. They are simple to make. Just draw houses with three bedrooms a piece. Label the house bedrooms ones, tens, and hundreds. Then name the houses hundreds, thousands, millions, etc. Students even love to make it look like a neighborhood. Students can also make number cards to fit into the houses.

Other practice is also available through self-checking task cards. Students can decipher expanded notation and word form to make the standard numbers. Students look at the task card and then build the number on the Place Value Houses. To check students simply flip over the card. Once the Place Value Houses are built, these task cards can make a great center!
 
Interested but don’t want to make them from scratch? No problem, try these products:​
 
Place Value Houses Project
https://www.teacherspayteachers.com/Product/Place-Value-Houses-Project-2003589
 
Place Value Task Cards – Self-Checking
https://www.teacherspayteachers.com/Product/Place-Value-192-task-cards-3347357
​

Math Mysteries – Mrs. J’s Resources
Revisiting and building on place value knowledge is a necessary task to set up students for success to learn new math concepts later on in the year. The place value math mystery “Case of The Puzzled Pirate” has been built as a fun activity to practice and consolidate a variety of place value skills in one. Its design for different levels allows for you to choose the best option for your students. Choose an earlier (or easier) grade level to refresh students before starting a new Place value unit, or choose the level that meets your standards to review content learned at the end of a unit. The added factor of the mystery will help students try and persevere with challenging sections, and will help you gauge just how much your students know (or don’t!)
​
Check out the  bonus video hook that comes with "Case of The Puzzled Pirate" to set the stage to engage!:
https://www.teacherspayteachers.com/Product/Place-Value-Review-Math-Mystery-Case-of-the-Puzzled-Pirate-3159372?aref=ghl6enif

Click on he grade level below to find out the Place Value skills and level of difficulty in each: 

The 2nd to 6th grade clue sheets are interchangeable to differentiate the activity for your students (as long as it is the same clue number). 

Practice Makes Perfect! – Kelly Malloy
Once your students have mastered the place value skills required for your grade level, you will want to make sure to practice and review them so that they don’t lose them! I Have, Who Has games are a great way to practice skills in the classroom. They are a great whole group activity that can be used for review, test prep, fluency, listening skills, and mental math. My students and I love using these games to review our skills and place value is no exception.
I have a special freebie Place Value I Have Who has game that you can download here.
https://www.teacherspayteachers.com/Product/Place-Value-I-Have-Who-Has-Game-1278062
I also have Daily Math Review Resources for 1st through 5th grade that not only review place value, but other skills as well!  You can find them here:
https://www.teacherspayteachers.com/Store/Kelly-Malloy/Category/Spiral-Math-Review-218629/Search:math+review