10) Addition and Subtraction within 100

Syllabus Content

Addition within 100 without renaming

• Add a 2-digit number and a 1-digit number

• Add a 2-digit number and tens

• Add two 2-digit numbers

Addition within 100 with renaming

• Add a 2-digit number and a 1-digit number

• Add a 2-digit number and tens

• Add two 2-digit numbers

Mental calculation involving addition

• Within 20

• Of a 2-digit number and ones without renaming

• Of a 2-digit number and tens

Subtraction within 100 without renaming

• Subtract a 1-digit number from a 2-digit number

• Subtract tens from a 2-digit number

• Subtract a 2-digit number from another 2-digit number

Solve problems involving addition and subtraction within 20

Learning Experiences

LE 2(d)

Use strategies such as count on, make 10 and subtract from 10 for addition and subtraction within 20 (before committing the number facts to memory) and thereafter within 100

LE 2(g)

Use base-ten set to illustrate the standard algorithms for addition and subtraction of 2-digit numbers

Teaching of renaming