#Decompose math numbers how to
#Decompose math numbers plus

I've decomposed 31 into its 10s and 1s.')

I also see that there is 1 one in the ones place. I see that there are 3 tens in the tens place to make 30. Now, if I were to decompose this number, the problem might be: How many tens and ones are in 31? Well, first I have to think about how many tens are in 31. I know that three tens is 10 + 10 + 10, or 30. ( 'Let's say that we read the problem 'How much is 3 tens and 1 one?' In this problem, I need to compose, or put numbers together.

#Decompose math numbers how to

Model Skill with Examples. Think aloud about how to compose or decompose a number.Decomposing numbers means breaking numbers down into their subparts.' 'Today, we are going to learn strategies for composing and decomposing numbers.' ) Explain the Skill/Concept. Define composing and decomposing numbers, and explain activity. ( 'Composing numbers means putting parts together to make a new number.If you are intervening to support your student's ability to compose and decompose numbers, you should start by explicitly teaching the skill. As you read, consider which of these interventions best aligns with your student's strengths and needs in the whole-learner domains. This skill will help your student solve simple math facts in his head or use invented algorithms to solve multi-digit addition and subtraction problems. This page includes intervention strategies that you can use to support your students in this area. Identifying Essential Variables InterventionsĪnother way to support your student's understanding of quantity is through composing and decomposing whole numbers.Monitoring Progress & Reflecting on a Solution Interventions.Planning and Executing a Solution Interventions.Understanding the Problem Interventions.Response to Error: Composing and Decomposing Numbers.Composing and Decomposing Numbers Interventions.Counting Interventions: Whole Numbers Greater Than 30 (Place Value).Counting Interventions: Whole Numbers Less Than 30.Ways to decompose the exact same fraction. And how would we visualize that? Well, we're saying So what could we put here? Well, we could say 0/9.

#Decompose math numbers plus

Got us all the way, because 1 plus 2 plus 4 is So let's say add first 1/9Īnd see where that gets us.

I'm going to try to addįour fractions here. See- actually, let me just write this out. Know, maybe we could add- let me give some space here This is 2/9 plus 3/9 timesĢ/9 is going to give me 7/9. The same denominator, we can just add the numerator. And we know that when weĪdd a bunch of fractions like this that have So notice, when I added 2/9 toģ/9 to 2/9, this equals 7/9. So what would this look like? So let's just drawīelow it, so that we can see how they match up. We can represent it as- let's do it as 2/9. But let's see if weĬan represent 7/9 as the sum of other fractions. So that's 1, 2, 3,Ĥ- you know where this is going- 5, 6, and 7. So let me get myself aīigger thing to draw with, so that I can fill this in fast. And 7/9 you could representĪs 7 of those equal sections. Of the different ways that we can represent 7/9. (Note: you could have made the problem lots easier by simplifying the fractions at the beginning into 1/3 and 1/3 and then just adding those, but that would defeat the purpose of learning how to add unlike denominators.) Now, you have two fractions with the same denominator, so you can add them as normal:

The least common multiple between 9 and 6 is 18 (you can learn how to find LCMs by using the search box in the top of any Khan Academy screen, if you don't know already). With all that out of the way, let's see that example: The easiest way to convert two fractions to the same denominator is to make each denominator the least common multiple of the two previous denominators. To convert a fraction into a different denominator, you have to multiply the numerator and denominator by the same number (in order to keep the actual value the same). You would need to convert the fractions so that they have the same denominator, and then add them by adding the values in the numerators and keeping the denominator the same.