Cause and Effect — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. The class hamster escaped from its cage overnight. In the morning, students found wood shavings all over the floor. What was the cause?
A) Wood shavings were on the floor.
B) The students arrived at school.
C) The hamster escaped from its cage.
D) The teacher cleaned the classroom.
The wood shavings on the floor are the effect, not the cause. They got scattered because the hamster broke out and pushed bedding through the cage opening.
2. Which signal word best completes this sentence? "The garden hose had a crack in it, ___ water sprayed in every direction."
A) because
B) since
C) so
D) before
The word 'so' fits in the middle of the sentence to introduce the effect. The crack let water shoot out in different directions instead of flowing through the nozzle.
3. Maya left her art project outside. It rained during the night. In the morning the paper was soggy and the paint had washed away. What was the effect of the rain?
A) Maya left her project outside.
B) The paper was soggy and the paint washed away.
C) Maya worked hard on her project.
D) It stopped raining in the morning.
The rain is the cause, and what it did to the project is the effect. Water soaks paper and lifts paint right off the surface, ruining the artwork.
4. Which sentence uses the word 'therefore' correctly to show cause and effect?
A) Therefore, the sun came up every morning.
B) She liked pizza, therefore she liked the color blue.
C) The road was blocked by a fallen tree. Therefore, the cars had to turn around.
D) Therefore is a difficult word to spell.
'Therefore' belongs at the start of a second sentence followed by a comma. The blocked road is the cause and turning around is the effect, with the word linking them clearly.
Part B: Fill in the Blank
Write the correct answer on each line.
1. The ants marched into the kitchen because someone left crumbs on the counter.
Ants follow scent trails to food sources. The word 'because' shows that the leftover crumbs are what attracted the ants into the kitchen.
2. The wind blew the papers off the desk, so she had to pick them all up.
The word 'so' links the wind's action to the cleanup that followed. Scattered papers all over the floor needed to be gathered before they got lost.
3. Because the book was so exciting, he stayed up past his bedtime to finish it.
'Because' is capitalized when it begins a sentence and introduces the cause. The exciting story made him want to keep reading instead of going to sleep.
4. The team practiced every afternoon. As a result, they won their first game of the season.
The phrase 'as a result' signals the outcome of an effort. Daily practice built the team's skills, leading to their first win.
5. Since all the seats on the bus were taken, he had to stand for the whole ride.
'Since' is capitalized at the start of the sentence and introduces the reason. With no empty seats, standing was his only option until the bus reached its stop.