## Tuesday, January 27, 2009

### Math Time, Story Time

Teaching Tip Tuesday

I have highly verbal boys. They like to read, write and TALK! Nothing makes them as happy as a good story. On the other hand, numbers just don't "move" them. They are not math phobic but they don't have an intrinsic motivation in this area.

I am a die-hard believer in teaching math concepts before drilling facts. It is sooooo important that kids understand what is happening in mathematical operations. By knowing what is "going on", they are better prepared for higher levels of math and problem solving and are more likely to retain the facts (like multiplication tables) that we want them to know. In order to keep my boys engaged and to lay a good foundation, I begin the teaching of each new math "segment" with manipulatives coupled with good stories. Here is my favorite example....

After my students have a good handle on place value, I use a chart like this:

First I have them write in the minuend and then create it with the units, rods and flats:

Then I demonstrate on the board how to write in the subtrahend while they copy it to their charts:

Next we discuss what happens in a subtraction problem (taking away) and I tell the following story while I demonstrate the subtraction procedures on the board and they work out the problem on the chart in front of them:

On your chart there are three houses, a ones house (I have them draw a rooftop over the ones column), a tens house (draw roof top over tens) and a hundreds house (rooftop over hundreds). In each house everything is placed in groups. In the ones house everything is in groups of one. (I give a few examples and relate it to the unit blocks). In the tens house everything is in groups of ten. (Once again I give a few examples and relate to the rods). In the hundreds house everything is in groups of one hundred (examples, relate to the flats).

Today, the mom of the ones house, Mrs. Ones, wants to bake a cake. She has four cups of sugar and needs seven cups to bake her cake (explain how this relates to the numbers on the chart and the manipulatives; demonstrate how four is insufficient). Since she does not have enough sugar, she decides to visit her next door neighbor, the tens mom, and ask to borrow some (I move my fingers as if walking on the board from the ones column to the tens then knock on the board). KNOCK-KNOCK-KNOCK!! Excuse me Mrs. Tens, could I please borrow some sugar for my cake? Does Mrs. Tens have enough sugar to loan Mrs. Ones? (Here's where the story goes in one of two directions.)

(If there is at least one in the tens place, lead the students to understand that Mrs. Tens can loan the sugar.) However, everything in the tens house comes in groups of ten. Mrs. Tens does not have one cup of sugar to loan but ten. (Have the students pick up one rod from the tens column and move it to the ones. Remind them that everything in the ones house must be in groups of one. Have them exchange the one rod for 10 units and replace them in the ones column) Now, Mrs. Ones has fourteen cups of sugar! She has enough to bake her cake. (Demonstrate on the board how to write the regrouped ten and then how to subtract.)

This chart shows the regrouping from tens to ones:

This chart shows the subtraction process:

This chart shows the ones place difference:

(The story continues with Mrs. Ten needing 30 cups of sugar to bake a cake the next day.) Because Mrs. Tens loaned ten cups to Mrs. Ones, she only has 20 cups. She cannot go to Mrs. Ones' house and ask her to return some of the sugar because that would be rude. Besides, Mrs. Ones already broke the ten into ones so they cannot return to her tens house. She decides to visit Mrs. Hundreds and ask her for some sugar. (Act out the same scenario with Mrs. Tens visiting Mrs. Hundreds. Demonstrate with manipulatives and the notation on the board. Complete the story with Mrs. Hundreds baking her cake and using the amount of sugar in the subtrahend's hundreds place.)

This chart shows the regrouping from hundreds to tens:

This chart shows the subtracted tens and the difference in the tens place:

This chart shows the subtracted hundreds and the difference:

Now, think back to when Mrs. Ones asks Mrs. Tens to loan her a cup of sugar. If there is a zero in the tens place then Mrs. Tens cannot loan any to her. What is Mrs. Ones to do? She cannot return home, so she decides to visit Mrs. Hundreds. (act out the moving and knocking on the board) Does Mrs. Hundreds have sugar to loan? Yes! She has five hundred cups. Remember, everything is grouped in hundreds and so she must loan it out in hundreds. She gives one hundred cups of sugar to Mrs. Ones.

What is Mrs. Ones to do with all of that sugar? She decides to be a good neighbor and give some to Mrs. Tens on the way home. (demonstrate on board and with manipulatives as you finish out the story) She must give the sugar to Mrs. Tens in groups of ten so she breaks the one hundred into ten groups of ten. Then Mrs. Tens gives one group of ten to Mrs. Ones. Mrs. Tens is left with ninety cups of sugar while Mrs. Ones takes ten home, giving her enough to bake her cake. (finish by demonstrating the subtraction steps)

This has been a hit in our home and at the school where I taught. May you have much success as you instruct your dear ones!

Happy Teaching!

argsmommy said...

I love the story! This fits in very nicely with what we are doing in Math U See. Thanks for sharing.

Kellie

Molly said...

This DOES fit in nicely with Math U See, which teaches that no more than 9 people can live in any of the houses on Decimal Street...9 units, 9 tens, 9 hundreds, etc. Each house has 9 beds, 9 toothbrushes, 9 chairs, etc. If the tens family goes on vacation, they get Mr. Zero to come stay at their place and feed the fish!

Heather said...

Thank you, I will have to remember this come fall. Although we aren't ready for subtraction. We're still trying to learn that 15 is a number which comes after 14 and before 16.