Primary 1 - Number and Algebra: Whole Numbers
Standard 1.NA-WN.2 - Complete the subtraction sentence by filling in the missing number with operands up to 18.
Included Skills: Subtraction
Addition and Subtraction • 2.1 concepts of addition and subtraction • 2.2 use of +, - and = • 2.3 relationship between addition and subtraction • 2.4 adding more than two 1 digit numbers • 2.5 adding and subtracting within 100 • 2.6 adding and subtracting using algorithms • 2.7 solving 1-step word problems involving addition and subtraction within 20 • 2.8 mental calculation involving addition and subtraction - within 20 - of a 2-digit number and ones without renaming - of a 2 digit number and tens • 2.9 work in groups to make addition and subtraction stories using concrete objects/pictures and write an addition or subtraction equation for each story. • 2.10 write two addition facts and two subtraction facts for a given number bond within 10. • 2.11 use strategies such as 'count on', 'count back', 'make ten' and 'subtract from 10' for addition and subtraction within 20 (before committing the number facts to memory) and thereafter, within 100. • 2.12 compare two numbers within 20 to tell how much one number is greater (or smaller) than the other by subtraction. • 2.13 achieve mastery of basic addition and subtraction facts within 20 through playing a wide range of games. • 2.14 use the base-ten set to illustrate the standard algorithms for addition and subtraction of 2-digit numbers.