Question

Choose the correct option to complete the addition sentence.

$5$ + $?$ + $7$ = $15$

• A. $5$ + $3$ + $7$ = $15$
• B. $5$ + $4$ + $7$ = $15$
• C. $5$ + $5$ + $7$ = $20$
• D. $5$ + $6$ + $7$ = $20$

Answer 1

The correct option is A $5$ + $3$ + $7$ = $15$

Step $1$: $5$ + $7$ = $12$

Step $2$: Count forward from $12$; we have: $13$, $14$, $15$. So, the missing number is $3$.