Finishing pass on send/receive number. Examples distributed more sensibly.

docs/reference/radio/send-number.md

@@ -1,14 +1,16 @@
 # Send Number
 
-Broadcasts a number data packet to other micro:bits connected via ``radio``.
+Broadcast a number to other micro:bits connected via ``radio``.
 
 ### Parameters
 
-* packet - a number to be transmitted.
+* num - a number to send.
 
-### Examples
+### Example: Broadcasting acceleration
 
-Broadcasts the value of ``acceleration`` x to other micro:bits.
+This example broadcasts the value of your micro:bit's ``acceleration`` in the `x` direction 
+(left and right) to other micro:bits.
+This kind of program might be useful in a model car or model rocket.
 
 ```blocks
 input.onButtonPressed(Button.A, () => {
@@ -18,7 +20,9 @@ input.onButtonPressed(Button.A, () => {
 
 ### Light level sender
 
-This example broadcasts the level of the light around it:
+This example broadcasts the level of the light around it.
+You can do some interesting things with it if you use it along with the
+[Mailbot](/reference/radio/receive-number) example.
 
 ```blocks
 radio.setGroup(99)
@@ -28,38 +32,6 @@ basic.forever(() => {
 })
 ```
 
-This example shows the light level from the sender (above):
-
-```blocks
-radio.setGroup(99)
-basic.forever(() => {
-    let level = radio.receiveNumber()
-    basic.showNumber(level)
-})
-```
-
-### Mailbot
-
-This example takes the signal from the light level sender (above)
-and shows a text string if the light level becomes much brighter.
-You can put the light level sender in your mailbox and it will
-tell you when someone opens the box. You can try this with a normal
-box too, like a present.
-
-```blocks
-radio.setGroup(99)
-let max = 0
-basic.forever(() => {
-    let level = radio.receiveNumber()
-    if (level > max) {
-        max = level
-    }
-    if (max > 10) {
-        basic.showString("ALERT")
-    }
-})
-```
-
 ### See also
 
 [receive number](/reference/radio/receive-number), [on data received](/reference/radio/on-data-received)