Tutorpip← About this lessonABCHide the answer keyDownload PDF
Coding · Ages 8+ · Set A
Mina's stone path
Scan to mark
on screen
A
Name
Date
Start Finish
Goal: 15 min
Score/ 11
Remember: A loop can sit inside another loop. The inside loop runs all the way through every time the outside loop goes round, so you multiply.

Read and answer

Read the story, then answer.

Three rows of fourMina and Teo were building a stone path, and Bo pushed a wheelbarrow full of flat gray stones. Mina needed twelve stones, in three rows with four stones in every row. Writing every step made a list that tumbled off the table, so she used a loop. Then she put one loop inside another. The outside loop said repeat three times. Inside it sat the inside loop: repeat four times, lay a stone. After the inside loop came step down. The inside loop laid a whole row, Bo stepped down, and the outside loop went round again. Three rows of four made twelve stones. Grandpa Joe's nesting dolls showed the idea: a smaller doll sits inside a bigger doll.
1
In Mina's program, how many times does step down run?
1243
2
The number of stones is the outside number plus the inside number.
TrueFalse
3
The inside loop runs all the way through each time the outside loop goes .
offawayround
4
Look at the program. How many stones does Bo lay in all?
71025
5
Look at this program. How many times does Bo step down?
3412

Count, order and fix

6
With the outside loop at 3 and the inside loop at 4, join each step to how often it runs.
  1. 1push the wheelbarrow
  2. 2lay a stone
  3. 3step down
  • A3 times
  • B12 times
  • C1 time
7
Put one row of the path in order.
  • Bo steps down
  • The outside loop goes round again
  • The outside loop starts a round
  • The inside loop lays four stones
8
The stones marched off the bed into the carrots. What is the mix-up to fix?
Change the 3 to a 4Add another lay a stone lineMove step down out of the inside loop, to just after it
9
In the buggy program above, how many times does Bo step down?
1234
10
The outside loop is repeat 5 times and the inside loop is repeat 4 times: lay a stone. How many stones?
92054
11
Teo sets a table with a loop inside a loop: one round per person, and each round puts out a fork, a spoon and a cup. How many things for 4 people?
7129
12
Draw the path Mina built: three rows with four stones in every row.
Scan the code at the top to mark this sheet on screenTake a photo of your answers or type them. It is marked for you automatically, and your score is kept.
Answer key · Set A
Mina's stone path
13 Step down comes after the inside loop, so it happens once for every row. There are 3 rows.
2False Loops multiply: 3 rows of 4 stones make 12, not 7.
3round For every turn of the outside loop, the inside loop runs from start to finish.
410 The inside loop lays 5 stones each time, and the outside loop runs it 2 times, so 2 x 5 = 10 stones.
54 Step down is inside the outside loop but after the inside loop, so it runs once for each of the 4 rounds.
61-C, 2-B, 3-A A step before both loops runs once. A step inside the inside loop runs 3 x 4 = 12 times. A step after the inside loop runs 3 times.
73, 4, 1, 2 The inside loop runs all the way through, then Bo steps down, and then the outside loop goes round again.
8Move step down out of the inside loop, to just after it Step down was inside the inside loop, so Bo stepped down after every stone. After the inside loop it happens once per row.
912 Step down is inside the inside loop, which runs 3 x 4 = 12 times, so Bo steps down 12 times.
1020 The inside loop lays 4 stones each round, and there are 5 rounds, so 5 x 4 = 20.
1112 Each person gets 3 things, and there are 4 people, so 4 x 3 = 12 things.
Mark each answer, count the right ones and write the score on the sheet.