## Saturday, 26 September 2015

### Shopping at Ikea (How we round numbers in real life)

Shopping at Ikea:

To help us further understand how we round numbers in our lives, we imagined we were university students moving into our first flat and needed to furnish it from Ikea.

We have a budget of 5 000 francs / euros / dollars to furnish our flat.

I gave the children a selection of Ikea catalogues based upon some countries we come from, currencies we are used to using, and their mother tongues.

This year, we have a Japanese student in our class still quite new to Switzerland so I also included the Japanese version of the Ikea catalogue.  We used an online currency converter to find out his budget would be 600 000 yen.  This caused a lot of interesting discussion about currency values!

They are given the Ikea catalogue via a google doc: Ikea rounding activity

As they 'buy' things from the catalogue, they copy and paste them on their google doc.  They record the price and what they round that price to (see examples below)

They need to round each item they buy and record on paper the rounded amounts just like we might do if we really were shopping there.

They completely LOVE this activity so much and are constantly asking each other how much they should round a particular item to. This peer-teaching helps solidify their understandings far more effectively than if I help them decide.

What the Google doc looks like:

Ikea catalogue in English      ( Dollars )

Ikea Catalogue in French      (Swiss Francs  = CHF)

Ikea Catalogue in German    (Swiss Francs =  CHF)

Ikea Catalogue in Spanish     ( Euros  costs in Spain)

Ikea Catalogue in Japanese   ( Japanese Yen)

You are about to move into your new flat and will be living alone.

You have a budget of CHF 5 000
= \$5 000 if you are using the English catalogue
= 5 000 euros if you are using the Spanish catalogue
= 600 000 yen if using the Japanese catalogue

to buy all the furniture you may need for when you first move into your home.

1. Look through the Ikea catalogue and select furniture you will buy.

2. Copy the image of each piece of furniture and paste below.

3. Beneath each piece of furniture, type the cost and then round the cost to what you think it ought to be rounded to so they can be mentally added easily.

4. After you copy and paste an image, shrink its size so your document is easy to read.

For example,

Cost:  CHF 369;  Round up to  CHF 400

Cost:  CHF 349;   Round up to  CHF  350

Cost:   CHF 669;   Round up to CHF 700
Cost:   CHF 12.95; ROUND to 13.00

4. As you are shopping, keep adding your rounded purchases on scrap paper.

5. When you think you have reached approximately CHF 5 000 (or \$5 000 or
5 000 euros or 600 000 yen), stop shopping.  Then use a calculator to add the exact total.

a)  Was your rounding estimating close or not?  Why or why not?

b)  Was rounding the prices a useful strategy or not?  Explain why or why not.

Cost: 3,99  euros               rounded:4,00  euros

This helps them discover a real life example of how we round numbers and the children eagerly wanted to continue doing this at home which makes it even more perfect.

Kids begging to be allowed to do maths learning at home?

Can it get any better than that?!? :)