Ray's New Primary Arithmetic by Joseph Ray Ray's New Primary Arithmetic by Joseph Ray    

Lesson 50: Review - Subtract 3 values, Counting Down by 2s, 3s, 4s, 5s, and 6s

Directions

Have children complete the below review problems.

Have children practice until they perfectly master the task.

Steps

STEP 1

• Have children use physical objects to demonstrate and solve these exercises, such as an abacus, toys, or beans.

STEP 2

• Have children write out each problem and solution in equation form. For example, children write '20, 18, 16, 14, 12, 10, 8, 6, 4, 2, 0' for 'Begin with 20, and subtract by 2's to 0.'

STEP 3

• Assess mastery by reading aloud the listed problems and having the children mentally compute and recite the solutions.
• If children have difficulties, work with physical objects again and then reassess.