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Lesson 9: Intro to addition with 2-digit numbers

# Adding 2-digit numbers without regrouping

## Want to join the conversation?

• What if you group the numbers before addition
• It would be the same concept except backwards, you would still get the same answers. 800+50+3=853 358=300+50+8
• Even though I just started this, I wonder how to do proportions? Not the x over 4 or anything. I mean like, 4:5 or something. So hard tbh. Or maybe i'm just slow. Please help. Thanks!
• I think you just break the work into parts and do it one by one sp that you do not get stressed or angry.👍
• Can we count by 2s to 100
• Yes. You would go by 2 50 times, because 2 x 50 = 100.
• why is subtraction a thing
(1 vote)
• I guess if you think about it it's because addition is a thing. Adding is putting groups together, so something needs to describe separating groups. We call this subtraction.
• Why is regrouping important? Why Ithink it is important is because for example you cant subtract 32 from 56. So you have to regroup riight?
• In an addition problem, you need to regroup if there are more than 10 ones or 10 tens. In a subtraction problem, you need to regroup if there are not enough ones or tens to subtract.
• can we use another kind thing to help us with math?
• What kind of thing will you want us to use to help you in maths?
(1 vote)
• Do you regroup the numbers?
• We group numbers to make them easier to work with. Because we use a base-10 number system, we group numbers in multiples of 10. Ten 1s are the same as one group of 10. One hundred 1s are the same as one group of 100. Most of the time, one group of 10 or one group of 100 is easier to work with than ten 1s or one hundred 1s.