<s>
The	O
QAMA	B-General_Concept
Calculator	I-General_Concept
is	O
a	O
calculator	B-Application
that	O
requires	O
users	O
to	O
provide	O
a	O
reasonable	O
estimate	O
of	O
the	O
answer	O
before	O
the	O
precise	O
answer	O
is	O
delivered	O
.	O
</s>
<s>
Estimation	O
is	O
seen	O
by	O
many	O
as	O
an	O
essential	O
part	O
of	O
mathematics	O
,	O
and	O
some	O
believe	O
that	O
the	O
presence	O
and	O
popularity	O
of	O
calculators	B-Application
could	O
inhibit	O
the	O
use	O
of	O
estimation	O
skills	O
.	O
</s>
<s>
A	O
physical	O
version	O
of	O
the	O
calculator	B-Application
was	O
released	O
for	O
sale	O
in	O
2014	O
,	O
with	O
apps	B-Application
for	O
smartphones	O
and	O
tablets	O
developed	O
in	O
2016	O
.	O
</s>
