\(a.1237+2914+1763+2086\)
\(\Leftrightarrow\left(1237+1763\right)+\left(2914+2086\right)\)
\(=3000+5000\)
\(=8000\)
a) 1237 + 2914 + 1763 + 2086
= (1237 + 1763) + (2914 + 2086)
= 3000 + 5000
= 8000
b) 14968 + 9035 – 968 – 35
= (14968 - 968) + (9035 - 35)
= 14000 + 9000
= 23000