Question

Estimate each of the following using general rule :
Make ten more such examples of addition, subtraction and estimation of their outcome.
ii) $796-314$

Answer 1

Step 1 : Evaluate subtraction by rounding off to nearest hundreds
Given, $796-314$
Round off to hundreds
$796\text{rounds off to}800$
$314\text{rounds off to}300$
Hence,
$796-314=800-300=500$

Step 2 : Make ten more such examples
Ten more such examples are

1. $330+280=300+300=600$
2. $3937+5990=4000+6000=10000$
3. $6392-3772=6000-4000=2000$
4. $5440-2972=5000-3000=2000$
5. $2175+1206=2000+1000=3000$
6. $1110-1292=1000-1000=0$
7. $910+575=900+600=1500$
8. $6400-4900=6000-5000=1000$
9. $3731+1300=4000+1000=5000$
10. $6485-4319=6000-4000=2000$