Question

From the given options, identify the addition equation with the same numbers as those in the subtraction equation given below, and find the missing number.
$15–7=$ __

• A. $15+8=7;8$
• B. $15+7=22;22$
• C. $7+7=15;7$
• D. $8+7=15;8$

Answer 1

The correct option is D $8+7=15;8$

Say: Let us begin by finding the missing number for the given equation.

Ask:
$\bullet$ How do we find the difference?
Ans: By subtracting the smaller number, i.e., $7$ from the bigger number, i.e., $15.$
$\bullet$ What is the difference?
Ans: $15–7=8$
$\bullet$ So, what is the missing number in the given equation?
Ans: $8$

Say: Now let's find the related addition equation.

Ask:
$\bullet$ How do you find the total of two numbers?
Ans: By adding two smaller numbers to get a bigger number.
$\bullet$ Using the same three numbers $7,8,$ and $15,$ what addition equation can be framed?
Ans: $7+8=15$ or $8+7=15$
$\bullet$ Which of these equations is used in the given options?
Ans: $8+7=15$

Hence, Option C is correct.

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