What One Adds to the Other is a free printable Grade 4 English worksheet on identifying what a second text supplies, aligned to Common Core standard RI.4.9. It prints 2 questions with an answer key on its own sheet of paper, in 25 versions, 23 of them with different questions, so no two pupils in the class work from the same page. Print it from the browser or download it as a PDF — no account, no email.
Set 1 of 25 · the same problems every time you open this link.
23 of these 25 sets ask different questions — this skill does not have 25 questions to give. The rest reorder them, so no two pupils have the same paper in front of them.
What One Adds to the Other
RI.4.9
NameDate
Read the text, then answer the questions.
1.Read the text, then answer the questions.
What a Coral Reef Is
A coral reef looks like rock and is built by animals.
A coral polyp is a soft creature the size of a pinhead. It draws calcium from the sea water and builds a hard cup around itself. Millions of polyps, cup upon cup, become a reef.
Inside each polyp live tiny algae. The algae make food from sunlight and pass most of it to the polyp. In exchange they get shelter and the polyp's waste. Neither could build a reef alone.
When the water gets too warm, the polyps expel the algae. Without them the coral turns white and starves. That is what bleaching means.
A reef takes centuries to build and can bleach in a single hot summer.
1. How is the coral partnership like the one in a lichen?
2. How is a reef different from a rock?
2.Read the text, then answer the questions.
How Penicillin Was Found
In 1928 Alexander Fleming went on holiday and left a stack of dishes on a bench. Each held a colony of bacteria.
When he came back, one dish had a spot of mould on it. Around the mould was a clear ring where the bacteria had died.
Fleming realised the mould was producing something that killed bacteria. He named it penicillin and published a paper. Almost nobody noticed.
Ten years later, Howard Florey and Ernst Chain read that paper and tried to make penicillin in quantity. That turned out to be the hard part: it took two thousand litres of mould fluid to treat one patient.
By 1944 the problem had been solved and penicillin was reaching soldiers in the field.
1. How is it different from the X-ray story?
2. How is this discovery like the discovery of X-rays?
LessonPrint · RI.4.9 · Set 1 · free to copy for classroom use
Answer key — What One Adds to the Other
Set 1. Prints on its own sheet.
1.1. Both are two organisms living together where each supplies what the other cannot make. 2. A reef looks like rock but is built by living animals, cup upon cup.
2.1. Penicillin needed sixteen years and other scientists to become useful; X-rays were useful almost at once. 2. Both were noticed by accident by somebody paying attention to something unexpected.
Questions about What One Adds to the Other
What does the What One Adds to the Other worksheet cover?
It practises identifying what a second text supplies — 2 questions for Grade 4, all on Common Core RI.4.9: Combine two texts on one topic to write about it properly. The instruction to pupils is “Read the text, then answer the questions”, and the answer key follows on the next sheet.
Which Common Core standard does What One Adds to the Other practise?
CCSS.ELA-LITERACY.RI.4.9 — RI.4.9, in the Reading: Informational Text domain for Grade 4. The published standard reads: “Integrate information from two texts on the same topic in order to write or speak about the subject knowledgeably.” The worksheet assesses that standard rather than a paraphrase of it.
What age or grade is this worksheet for?
What One Adds to the Other is written for Grade 4, typically ages 9-10. It is one of the sheets on RI.4.9, so it suits any pupil working at that standard — including older pupils revisiting it and younger ones working ahead.
Does What One Adds to the Other come with an answer key?
Yes. All 2 answers are generated from the same problems as the questions, so the key cannot drift out of step with the sheet. It starts on a fresh sheet of paper, after the questions, so it is not handed out with the class by accident.
How many different versions of What One Adds to the Other can I print?
25 versions, of which 23 ask genuinely different questions — this skill does not have 25 distinct questions to give, so the rest reorder them and no two pupils still share a paper. Set 1 downloads all 25 as one PDF.
Is What One Adds to the Other free to print and photocopy?
Yes. What One Adds to the Other, its answer key and its 25 versions are free to print and photocopy for your own class, with no account, no email capture and no subscription at the download step. Please do not resell them or republish them as your own.
More practice for RI.4.9
Combine two texts on one topic to write about it properly.