Math AI Tutor

FOR 4TH GRADE

NUMBER AND OPERATIONS is a common core content. Common core content means it touches K-12 students.

The State expected the 4th grade student to master the concept of distributive property of addition to solve multiplication problem. Why because it is easier to multiply 78 x 10 , you got 780 quick answer using mental computation. Next it is also easy to multiply 78 x 5 because you remember your table 10 multiplication table and do mental calculation
78 x 5 = 390. Finally you apply addition. So even without calculator you can do big number multiplication using distributive property of addition.