Question

Observe the number line, and identify the missing number to complete the given subtraction equation.

• A. (i) 18, (ii) 9
• B. (i) 9, (ii) 18
• C. (i) 8, (ii) 18
• D. (i) 18, (ii) 8

Answer 1

The correct option is A (i) 18, (ii) 9

Say:
Let’s observe the number line, and identify the missing numbers in the equation.

Steps:

• From 18, 8 jumps are taken backward to reach 10.
• 18 - 8 = 10.
• From 10, 1 more jump is taken backward to reach 9.
• 10 - 1 = 9.
• In all, 9 jumps are taken backward from 18 by breaking apart 9 into 8 and 1.
• 18 - 9 = 9.
• Hence, option A is the answer.