Trace the loop: what is printed?: coding worksheet for Grades 9–10, page 1 preview

Coding worksheet · Computers & Digital Literacy

Trace the loop: what is printed? · Grades 9–10

Read 6 short Python programs about for, while and nested loops and work out by hand what each one prints or the final value of a variable. Builds careful code tracing.

Grades 9–10 · ages 14 to 16
Easy
35 to 45 minutes
1 page
Free

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

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The programs to trace

Directions: Trace each program line by line without a computer. Keep a note of every variable as it changes, then write exactly what the program prints or the final value.

1 What is printed?
1 n = 7975
2 total = 0
3 while n > 0:
4 total += n % 10
2 What is printed?
1 nums = [7, 16, 19, 35, 29]
2 best = nums[0]
3 for n in nums:
4 if n > best:
5 best = n
6 print(best)
3 What is printed?
1 n = 184
2 steps = 0
3 while n > 1:
5 steps += 1
6 print(steps)
4 What is printed?
1 total = 0
2 for i in range(1, 5):
3 for j in range(2):
4 total += i
5 print(total)
5 What is printed?
1 text = "planet"
2 result = ""
3 for ch in text:
4 result = ch + result
5 print(result)
6 What is printed?
1 def double(n):
2 return n * 2
3 total = 0
4 for i in range(1, 5):
5 total += double(i)

What your child practices

Your child builds careful code tracing. The skill is “Loops”: use repetition to shorten programs.

Grades and ages: Grades 9–10, ages 14 to 16
Time: About 35 to 45 minutes
Subject: Computers & Digital Literacy
Level: Easy for Grades 9–10
Answer key: Yes, for grown-ups who sign in
Printing: 1 page, US Letter or A4, low-ink option
Updated: October 15, 2026

How to use it

Work through the first program together, one line or arrow at a time. Then let your child work through the rest, showing their thinking on the page. It is one of the easier sheets for Grades 9–10, good as a warm-up or a first look at the skill.

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

Tip for grown-ups: Have your child write each variable's value beside its line as they trace.

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