4.NBT.B.5

Multiply a whole number of up to four digits by a one-digit whole number, and multiply two two-digit numbers, using strategies based on place value and the properties of operations. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.

Multiply up to four digits by a one-digit number. Multiply two-digit numbers. Both of these skills can be learned using concrete, visual, and abstract methods. Next, give your students this challenge. Its only prereq is being able to multiply a one-digit number by a two-digit number. After that, give your students this challenge. Finally, give your students this challenge. Its only prereq is being able to double a two-digit number.