$Complex numbers: warm-up: math worksheet for Grade 12, page 1 preview$

Math worksheet · Mathematics

Complex numbers: warm-up · Grade 12

Add, subtract and multiply complex numbers. 20 problems at a warm-up level for Grade 12, with an answer key for grown-ups.

Grade 12 · ages 17 to 18
Easy
30 to 40 minutes
2 pages
Free

The answer key is a separate page for grown-ups. Sign in to download it.

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The 20 problems on the sheet

Directions: Simplify. Remember i² = −1.

1. (9 − 6i) − (−6 − 3i) =
2. (−9 − 6i) − (1 + 2i) =
3. (−1 − 4i) + (−7 − 9i) =
4. (−2 + 3i) − (−3 − 9i) =
5. (−5 − 3i) − (8 − 2i) =
6. (1 + 2i) + (7 + 7i) =
7. (−5 − 8i) − (−9 + 4i) =
8. (0 − 7i) − (3 − 7i) =
9. (−9 − 7i) − (7 + 9i) =
10. (8 − 2i) + (2 − 4i) =
11. (9 − 4i) − (−4 − i) =
12. (−6 − 9i) − (−8 + 7i) =
13. (−2 − 9i) + (7 + 7i) =
14. (1 + 8i) − (4 − 2i) =
15. (4 + 9i) − (−2 + 3i) =
16. (−5 + 9i) − (−6 − 8i) =
17. (1 + 0i) + (3 − 3i) =
18. (−4 − 2i) + (3 − 5i) =
19. (8 − i) − (−3 − 3i) =
20. (−9 − 8i) + (6 + i) =

What your child practices

Your child practices math for Grade 12 with this math worksheet.

Grades and ages: Grade 12, ages 17 to 18
Time: About 30 to 40 minutes
Subject: Mathematics
Level: Easy for Grade 12
Answer key: Yes, for grown-ups who sign in
Printing: 2 pages, US Letter or A4, low-ink option
Updated: October 15, 2026

How to use it

Try the first question together so the format is clear. Then let your child work through the rest, showing their thinking on the page. It is one of the easier sheets for Grade 12, good as a warm-up or a first look at the topic. Its 2 pages split well across two sittings.

An answer key comes with it as a separate page that grown-ups download after signing in.

Tip for grown-ups: Check the first three problems together before your child carries on alone; most mix-ups show early.

Done on paper? A grown-up can record it on the child's page in PlayOwl; downloading alone doesn't count as finished.