The Boy on the Verge Jolly Phonics · Step 3, Unit 3: soft g as in giant

The Boy sits on the grass with a rock in one hand and a feather in the other. 'The rock will drop fast,' he says. 'It has huge mass. The feather will float down slow, like a little cloud.' He lifts them both up, all set to drop them. But then he stops. 'Wait. How much mass is in the rock? A bit? A lot? I must check.'

Look at this rock. It is hard and solid, like a gem. Deep in the ground, heat and time press it firm. A huge beast can grip it in its trunk, but the rock keeps its shape. In the hot sunshine it stays cool and strong. Try to bite a rock. No, wait. Do not.

'A rock is a bit like this giant beast,' The Boy says. 'They both have huge mass. They both stay still.' He does a test. He presses the beast. He presses and presses. His feet slip on the ground. The beast does not shift one bit. It just sits and blinks. 'Gee,' The Boy pants. 'The beast wins.'

A feather is not like a rock at all. It is soft and light, and it can float on the wind. The Boy lifts them both up, one in each hand. The rock drags his arm down. The feather just taps his fingers. 'How strange,' he says. 'One can float away. One just sits there.' But how much mass is in the rock? He must get the true number.

The Boy lifts the rock up high and squints at it. A number hides deep in that stone. A number locked away. 'Is it one kilogram?' he asks the rock. 'Ten? Some huge number?' The rock does not say a thing. You can not get the true mass just by feel. The true number is like a magic code. You need the best tool to get it.

'Dad!' The Boy yells. 'Help!' Dad charges up the path with a mass tool. 'Did I hear a call to check mass? This is the best tool!' Dad grins. He is far too keen. The Boy peeks out, eyes wide. Now they can get the true number.

Dad holds up a flask. 'First we need a thing with a true, set mass. This flask, full to the top, is one kilogram. One flask, one kilogram.' Dad grins like he is up on a stage. He is so proud. 'Now,' Dad says, 'we can check the mass on any thing at all.'

'Dad, does a big count mean more mass?' 'No!' Dad says. 'Think. Ten cows on one pan. A large box packed with dogs on the other pan. Which side wins?' 'The dogs!' The Boy yells. 'There are lots more dogs!' 'No! The cows win. Mass is not a count. It is how much stuff is packed inside.'

The Boy looks at the hills, the sky, the vast planet under his feet. 'Can we check the mass on the planet?' he whispers. Dad grins. 'No mass tool is that large! But here is the trick. We do not need one. We can use maths.' The Boy gasps. Maths can do that? What strange magic is this!

Dad shows The Boy a vast grid, packed with jugs. 'The planet has the same mass as all the jugs in the grid,' Dad says. 'A giant number.' The Boy tries to see that many jugs in his mind. He can not. No one can. The number is so big it can fill a page and still run on. Just try to say it out loud.

'But Dad, what about my feather?' The Boy asks. 'How many feathers match one kilogram?' Dad sets up the mass tool. On one pan, the flask. On the other pan, feathers. They pile the feathers up and up. The heap bulges. It gets so tall! Then the tool is still. Each side has the same mass. But one side is small, and one side is a huge feather heap.

The Boy tilts his head back. Rain starts to fall. One raindrop lands on his hand. He can just feel it. It has next to no mass. 'But drop by drop, raindrops make all the sea,' he says. Small things add up. Light things can be a huge load. The planet has so many tricks like that.

The Boy gets on the mass tool and checks his own mass. More than a melon! Way less than the giant beast! He picks up the rock. He picks up the feather. He lifts them both, just like before. 'I know all about them now,' he says with a grin. 'All set? Drop them both!' Which one hits the ground first? Go and check!