$\sqrt{49}$ = 7

Subtract$-21$ from$49$ and then $49$ from$-21$.

Is $49-(-21)=-21-49$ ?

$49\times 98=49\times \_\_\_\_\_\_\_\_\_\_\_\_-2\times 49.$

Find $(-49)÷49$

$35+49+0=49+\_\_\_\_\_\_\_\_\_\_\_+35$

Estimate the following :

$49\times 49$