Using a Block

- (void) shrinkFrame {
    void (^myBlock)(void);
    myBlock = ^(void) {
        CGRect frame;
        frame = self.frame;
        frame.size.width /= 1.5;
        frame.size.height /= 1.5;
        self.frame = frame; 
    };
    
    [self animateBlock:myBlock];
}

- (void) animateBlock:(void ( ^ )( void ))theBlock {
    [UIView beginAnimations:nil context:nil];
    theBlock();
    [UIView commitAnimations];
}