Increasing

Chain 6  Row 1: *Starting in 4th ch from hook (counts as 1 tr here and throughout), tr in next 3 ch.* This gives you the first row and the first block of 4 trebles completed. Each row is made up of these little blocks of 4 sts. Turn your work now.

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Row 2: 6 ch, rep Row 1 from * to *.  **Sl st into the top of last tr of last row, 3 ch (counts as 1 tr), make 3 tr in side of the same tr stitch.** This has completed your second row. Turn your work again.

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Row 3: 6 ch, repeat from * to * then work from ** to ** across to complete the row. In this way you will build up the blocks from one corner to the next row upon row, making the blanket grow outwardly from a corner.

Decreasing

Once you've reached your desired width you're then ready to start decreasing.

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Next Row: Sl st across 4 tr, 3 ch (counts as 1 tr), 3 tr in side of same tr, repeat from ** to ** until last tr block, sl st into top of tr. Turn.  

Repeat this row to decrease back until you've one tr block left, then fasten off.