Question

There were $13$ people in line to buy tickets. If only $6$ of them are left, how many have already bought the tickets? Complete the equation below.
$6+$ ___ $=13$

• A. $8$
• B. $9$
• C. $6$
• D. $7$

Answer 1

The correct option is D $7$

Say: We need to find the number of people who already bought tickets.
Since subtraction is an unknown addend problem, we will use subtraction to complete the given addition equation.

Ask:
$\bullet$ How many people are in the line to buy tickets?
Ans: $13$
$\bullet$ How many are left to buy tickets?
Ans: $6$
$\bullet$ How do we find the difference?
Ans: By subtracting the smaller number, i.e., $6$ from the bigger number, i.e., $13.$
$\bullet$ What is the difference?
Ans:$13–6=7$
$\bullet$ So, what is the missing number in the given equation?
Ans: $7$
$\bullet$ What is the related addition equation?
Ans: $6+7=13$

Hence, Option A is correct.

WB: If required, use the whiteboard to represent the bigger and smaller number as shown and write the subtraction equation.

Probing Question:
Q. Is there another subtraction equation that can be framed?
A. $13–7=6$