Answer
Estimate: 22 + 4 = 26
Exact: $26\frac{5}{24}$
Work Step by Step
$21\frac{7}{8}+4\frac{5}{15}$
First Lets Find Estimate:
$21\frac{7}{8}$ rounds to 22
$4\frac{5}{15}$ rounds to 4
Now, $21\frac{7}{8}+4\frac{5}{15}$ = 22 + 4 = 26
Now find Exact:
$21\frac{7}{8}+4\frac{5}{15}$
= $\frac{21\times8+7}{8}+\frac{4\times15+5}{15}$
= $\frac{175}{8}+\frac{65}{15}$
= $\frac{175\times15}{8\times15}+\frac{65\times8}{15\times8}$ (LCM of 8 & 15 are 120)
= $\frac{2625}{120}+\frac{520}{120}$
= $\frac{3145}{120}$
= $26\frac{25}{120}$
= $26\frac{5}{24}$
