If you have done the Eureka Math Lesson 25 Homework 4.3 and want to check if you did a good job, this article will show the answer key of the Lesson 25 Homework 4.3. But, if you have not done your homework, then you are able to solve this Homework. Try to answer all the questions first, next you will be able to check the answer here.

**The Answer Key for Eureka Math Lesson 25 Homework 4.3**

- A student used the sieve of Eratosthenes to discover all prime numbers less than 100. Make a step-by-step set of directions to show how it was completed. Try to use the word bank to help guide your thinking when you write the directions. Several words may be utilized only once, more than once, or not at all.

1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |

11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |

21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |

31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 |

41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 |

51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 |

61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 |

71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 |

81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 |

91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | 100 |

Directions to complete the sieve of Eratosthenes activity:

Word Bank:

- composite
- cross out
- number
- shade
- circle
- X
- multiple
- prime

The answer of the first question:

Primes numbers less than 100 are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97.

Explanation: First, you are able to circle 3, because it is the next number which is not circled or crossed off. You cross off every multiple of 3 except for the number 3. You skip count by threes to discover the multiples.

Then, you are able to continue the process, first for the multiple of 5 and then for the multiple of 7.

You have to circle 11 because 11 is the next number which is not circled or crossed off. You notice that every multiple of 11 is already crossed off.

You do not have to cross off the multiple of 13 because they are crossed off already.

You have to realize that when you circle any of the other numbers which are not already crossed off their multiples have already been crossed off. Also, you shade every crossed out number.

You are going to see that the process helps you to find the numbers from 1 to 100 which are prime and the numbers from 1 to 100 which are composite.

- What do all of the numbers which are crossed out have in common?

The answer of the second question: Composite

- What do all of the circled numbers have in common?

The answer of the third question: Prime

- There is one number which is neither crossed out nor circled. So, why is it treated differently?

The answer of the fourth question: Actually, the answer can vary. For this case, you are able to watch this video by clicking this link here.

**About Eureka Math**

Talking about the Eureka Math Lesson 25 Homework 4.3, now you may want to know more about Eureka Math. Well, here we are going to discuss what Eureka Math is. According to research, Eureka Math is a holistic curriculum especially for Prekindergarten through Grade 12. The curriculum of Eureka Math sequences mathematical progressions in the modules which are created by the experts. Of course, the curriculum of Eureka Math will make math fun to learn and teach.

Need to know that Eureka Math provides professional development, learning materials and also a community of support. Aside from that, the curriculum of Eureka Math is committed for supporting you throughout implementation. The development sessions that Eureka Math built are specially created to complete the educators with the tools which they must support the new and continuing users of Eureka Math.

For your information, Eureka Math gives the Teacher Resources Pack including a selection of instructional materials and tools such as:

- Curriculum Maps
- Curriculum Overviews
- Materials Lists
- Standards Checklists
- Pacing and Preparation Guides

**How Does Eureka Math Work?**

By the way, how Does Eureka Math work? Keep in mind that Eureka Math’s key successful component is collaboration, meaning that Eureka Math enables the educators, students, the curriculum writers, the exchanges resources, and the best practises to stay connected. Also, Eureka Math will offer you a complement of Prekindergarten through Grade 12 print materials including the student workbooks, the Teacher Editions etc. Aside from that, the curriculum of Eureka Math also gives the Spanish language editions available for Grade K-8 that gives the teachers lots of methods to differentiate the instructions, access the student’s learning and also give some extra practises.

The Eureka Math Curriculum owns a Digital Suite. It gives the users two exceptional online resources. The Eureka Math Digital Suite will include a Navigator. It is a digital version of the Prekindergarten via the Grade 12 curriculum. Also, that Eureka Math Digital Suite gives the Teach Eureka Video Series which is a collection of on-demand PD videos which accompanies the curriculum. Also, you are going to discover the term ‘Affirm’ in the Eureka Math curriculum. It is a digital mid-module of Eureka Math curriculum and end-of-module assessment. It has a practice tool that completes the educators with a robust database of formative items. Also, it is analytics tool which is designed to help the teachers to track the student progress and identify areas of need.

Apparently, Affirm is giving the students with enough opportunity for extra practice and preparation for standardized assessments. Also, the curriculum of Eureka Math gives the grade-level analyses of how the curriculum straightens with the standards for all 50 states.