Using the unmarked number line to add and subtract
Using the unmarked number line to add and subtract
Last updated at October 9, 2025 by Teachoo
Transcript
Using the unmarked number line to add and subtractWe can use the unmarked number line to add & subtract We use these rules For positive numbers, we go to the right For negative numbers, we go to the left In our calculations, we need to have a plus sign in the middle Example: For (–2) – (+3), we write (–2) + (–3) Solve 85 + (– 60) on number line 85 + (–60) Since 85 is positive, we mark 85 to the right of zero And since 5 positive, we move 5 steps to the right we reach 25 Thus, 85 + (–60) = 85 – 60 = 25 Solve (–100) – (+250) on number line (–100) – (+250) = (–100) + (–250) Since (–100) is negative, we mark (–100) to the left of zero And since (–250) is negative, we mark (–250) to the left we reach (–350) Thus, (–100) – (+250) = (–100) + (–250) = –100 – 250 Taking – common = – (100 + 250) = – 350