Teaching 3rd graders compatable number? Is there a rule? I have taught them to group numbers that add up to ten. I also told them think of it as rounding to nearest 5. Am I steering them in the right direction?
The rule is to choose a near number that is easier to add. Rounding to nearest 5 will work.
For instance, add 3+17+21+12
using compatible numbers
5+15+20+10=50
The use of compatable numbers is an aid to doing arithmetic. It works not as good on multiplying and dividing, but it does give an estimate, but at 3rd grade, you are not there yet.
Thank you so much. Just adding two digit numbers and in the book there is only one sentence about compatable numbers and wanted to further understand how to teach it to the students since it is in our State Curriculum for third graders to know (TEKS). 683+52 ----I tell the students 685 will be compatable to 683 and 50 will be compatable to 52 and then add 685+50 = 735.
What are compatible numbers her teacher has her
Round to the nearest number 25,50,75 an the her numbers are 68,39,17,82
What is greatest perimeter of a rectangle with an area of 39 square feet
156
Yes, you are definitely steering them in the right direction!
In mathematics, compatible numbers are numbers that are easy to work with mentally because they are close to the actual values involved in a calculation. Compatible numbers help students to estimate, simplify calculations, and make the process of solving problems easier.
To teach third graders about compatible numbers, you can start by explaining the concept of rounding to the nearest ten. Rounding is the process of finding a nearby number that is easier to work with.
One way to find compatible numbers is by using the strategy you mentioned: grouping numbers that add up to ten. This method helps students quickly identify pairs of numbers that can be combined to make a compatible number. For example, 7 and 3 can be grouped together because they add up to 10.
Another strategy you mentioned is thinking of rounding to the nearest five. This is also an effective approach because rounding to five is easier and more manageable for students. For example, if they have to round 46 to a compatible number, they can round it to 45 or 50, which are both multiples of 5.
It's important to reinforce the understanding that compatible numbers are not "exact" solutions, but rather approximations that make calculations easier. Encourage your students to use compatible numbers when estimating or doing mental math rather than for exact calculations.
Overall, by teaching students to group numbers that add up to ten and think about rounding to the nearest five, you are providing them with useful strategies for finding compatible numbers and making mental calculations easier.