B1 Mathematics · Term 1 Week 12: Number Operations (Addition, Subtraction, Multiplication and Division)

Lesson notes

Learning Objectives

Indicator: B1.1.2.2.2 - Use relationship between addition and subtraction to demonstrate understanding of equality for numbers within 20

By the end of the lesson, learners can:

Write the related addition fact for a given subtraction fact within 20 (e.g., for 10 - 8, write 8 + 2 = 10).
Write the related subtraction fact for a given addition fact within 20 (e.g., for 6 + 7 = 13, write 13 - 7 = 6).
Fill in a missing number in a number sentence by using the relationship between addition and subtraction (e.g., 9 + [] = 15 means [] = 15 - 9 = 6).
Explain in their own words why 10 - 8 = 2 and 8 + 2 = 10 mean the same thing, using objects or drawings to justify their answer.
Solve simple word problems within 20 by choosing either an addition or subtraction fact that is related to the situation.

Sign in with your phone number to read the full note and download the GES plan - free.

Sign in with phone number

Curriculum details

Strand: Number (Strand 1)
Sub-strand: Number Operations (Addition, Subtraction, Multiplication and Division) (1.2)
Content standard: B1.1.2.2 - Demonstrate an understanding of the concept of equality
Indicator: B1.1.2.2.2 - Use relationship between addition and subtraction to demonstrate understanding of equality for numbers within 20
Suggested placement: Term 1, Week 12 (Week 12 of the year)
Our suggestion, laid out in curriculum order across three terms of twelve weeks. NaCCA does not fix the week, so follow your school's scheme of learning.
Curriculum reference: Mathematics Curriculum for Primary Schools (Basic 1-3), 2019, p. 7
Transcribed from the official NaCCA publication. Check this page against the source.

Exemplars (from the NaCCA curriculum)

E.g. 1. Demonstrate an understanding of the relationship between addition and subtraction by: transforming a subtraction as an equivalent addition and vice versa (For example, subtracting eight from 10 (10 - 8) is the same as identifying the number that must be added to 8 to make 10)
10 - 8 = What? Means 8 + What? = 10