Playdates

Playdate focus

Your child’s numbers are going above 100, and their adding and subtracting involves two-digit numbers. Practice 2-digit and 3-digit expanded form and place value with them.

Activities properties

These involve two-digit addition and subtraction.

Many objects

Relating math concepts to physical objects is often the best approach for young children. The difficulty here is that it is not so easy to have hundreds of objects in the first place, and it can also be unwieldy to deal with such a large collection. In addition to having groups of ones and tens of some object, one strategy is to use symbolic place holders for large groups, such as 100s. You could have several pieces of paper or wood on which you have written “100.”

Use objects

Practice having your child represent various quantities using objects grouped in ones, tens, and hundreds. For example, ask how 325 would be represented using these objects. Include examples such as 206, 430, and 500 that have zero things in one or more categories. Also, lay out collections of ones, tens, and hundreds and ask your child to name the number for this quantity.

Use expanded form

Once your child is thoroughly comfortable with the connection between numbers and their quantities, start using numerals and expanded form to represent the numbers. Take a number, such as 325, for example. Represent it with quantities for hundreds, tens, and ones, and then use the quantity representation to write the number in expanded form as 325 = 300 + 20 + 5. Do this same practice in the opposite direction by writing 100 + 40 + 6, representing it with physical groups of hundreds, tens, and ones of objects, and then asking what the total number is.