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## Subtracting decimals

Current time:0:00Total duration:1:53

# Subtracting decimals: 10.1-3.93

CCSS Math: 5.NBT.B.7

## Video transcript

Let's try to calculate
10.1 minus 3.93. And I encourage you
to pause this video and try it on your
own first, and then we can think about whether
we did it the same way. So let's just
rewrite it, aligning the decimal and the
different place values. So 10.1 minus-- the 3
is in the ones place, so I'll put it right
under the 0-- 3.93. Now, let's just try
to calculate this. Now, before we subtract, we
want all the numbers on top to be larger than the
numbers on the bottom. And we don't even
have a number here. We could stick a 0 here. Let me do that in a
different color here. We could stick a 0 here. 10.1 is the same thing as 10.10,
but we still face an issue here. 0 is less than 3. 1 is less than 9. 0 is less than 3. So we're going to do a
little bit of regrouping. So let's do that regrouping. So we could take a 10 away,
one 10 away, and then one 10 is the same thing as 10 ones. So I could write a
10 in the ones place. And I could take
one of those ones away so I'm going
to have nine ones, and give that one
to the tenths place. Well, one is 10 tenths. 10 tenths plus 1 tenth
is going to be 11 tenths. Now, I could take
one of those tenths away and give it to
the hundredths place. 1 tenth is 10 hundredths. And now I have a higher
digit in the numerator, or at least as equal
in the numerator as I have in the denominator. So 10 minus 3 is 7. 10 minus 9 is 1. I have the decimal. 9 minus 3 is 6. And then I have
nothing over here. So 10.1 minus 3.93, 6.17.