Question

Fill in the missing numbers/words.

$8438+\_\_\_\_=8440.$

Answer 1

Given: $8438+\_\_\_\_=8440.$

Now if we add $2$ in $8438$ we get,

$\mathrm{Th}\mathrm{H}\mathrm{T}\mathrm{O}\mathrm{carry}-\mathrm{over}18438+28440$

Hence, $8438+\mathbf{}\mathbf{2}=8440$.