diff --git a/docs/blocks/logic/boolean.md b/docs/blocks/logic/boolean.md
index c6873540..15df1b5f 100644
--- a/docs/blocks/logic/boolean.md
+++ b/docs/blocks/logic/boolean.md
@@ -86,7 +86,7 @@ if (led.point(1,1) && led.point(2,2)) {
 When you compare two Numbers, you get a Boolean value, such as the comparison `x < 5` in the code below:
 
 ```blocks
-let x = math.random(5)
+let x = Math.random(5)
 if(x < 5) {
    basic.showString("low");
 } else { 
diff --git a/docs/lessons/headbands/activity.md b/docs/lessons/headbands/activity.md
index a8c467bf..ea7c7618 100644
--- a/docs/lessons/headbands/activity.md
+++ b/docs/lessons/headbands/activity.md
@@ -5,7 +5,7 @@
 Your beginning code should look like this:
 
 ```blocks 
-let coll = (<string[]>[])
+let coll: string[] = []
 coll.push("puppy")
 coll.push("clock")
 coll.push("night")
@@ -27,7 +27,7 @@ game.startCountdown(30000)
 Let's add more words for the player to act out! But first, we need to increase the time in one round to give the player more time get through all the words. Let's change the `game->start countdown` statement.
 
 ```blocks
-let coll = (<string[]>[])
+let coll: string[] = []
 coll.push("puppy")
 coll.push("clock")
 coll.push("night")
@@ -52,7 +52,8 @@ game.startCountdown(60000)
 Now let's add 5 more words to our list of charade words. Right above the the line `word:=coll->at(index)` add 5 lines that say `coll->add("")`. In this example, we will add the words **bicycle, telephone, sun, car, and ant** but you can add whatever words you like.
 
 ```blocks
-let coll.push("puppy")
+let coll: string[] = []
+coll.push("puppy")
 coll.push("clock")
 coll.push("night")
 coll.push("cat")
diff --git a/docs/lessons/headbands/quiz-answers.md b/docs/lessons/headbands/quiz-answers.md
index d7c3c7b7..697cbec7 100644
--- a/docs/lessons/headbands/quiz-answers.md
+++ b/docs/lessons/headbands/quiz-answers.md
@@ -19,7 +19,7 @@ A 'collection' is a group of variables of the same type stored together. A 'coll
 ## 2. Consider the following lines of code.
 
 ```blocks
-let coll = (<string[]>[])
+let coll: string[] = []
 coll.push("puppy")
 coll.push("clock")
 ```
@@ -35,7 +35,7 @@ basic.showString(coll[0], 150)
 ## 3. Consider the following lines of code.
 
 ```blocks
-let coll = (<string[]>[])
+let coll: string[] = []
 coll.push("puppy")
 coll.push("clock")
 coll.push("cat")
@@ -52,7 +52,7 @@ basic.showString(coll[2], 150)
 ## 4. Consider the following line of code.
 
 ```blocks
-let coll = (<string[]>[])
+let coll: string[] = []
 ```
 
 Write the five (5) lines of code that will add the following five words to `data->coll`: puppy, clock, night, cat, cow.
@@ -60,7 +60,8 @@ Write the five (5) lines of code that will add the following five words to `data
 <br/>
 
 ```blocks
-let coll.push("puppy")
+let coll: string[] = []
+coll.push("puppy")
 coll.push("clock")
 coll.push("night")
 coll.push("cat")
diff --git a/docs/lessons/hero/activity.md b/docs/lessons/hero/activity.md
index 59fbbccb..fd6b1a8e 100644
--- a/docs/lessons/hero/activity.md
+++ b/docs/lessons/hero/activity.md
@@ -211,7 +211,7 @@ Let's setup the logic for the food and the ghost to be in different quadrants. F
 let hero = game.createSprite(2, 2);
 let food = game.createSprite(4, 4);
 let ghost = game.createSprite(0, 0);
-let ghost.change(LedSpriteProperty.Blink, 100);
+ghost.change(LedSpriteProperty.Blink, 100);
 food = led.brightness() == 8;
 while (true) {
     basic.pause(400);
@@ -265,7 +265,7 @@ while (true) {
     }
 
 }
-0.set(LedSpriteProperty.X, 4);
+ghost.set(LedSpriteProperty.X, 4);
 
 
 ```
diff --git a/docs/reference/led/plot-leds.md b/docs/reference/led/plot-leds.md
index ca26dde1..dd796a45 100644
--- a/docs/reference/led/plot-leds.md
+++ b/docs/reference/led/plot-leds.md
@@ -3,11 +3,11 @@
 Display an [Image](/reference/images/image) on the BBC micro:bit's [LED screen](/device/screen). NOTE: `basic -> plot image` has been replaced by `basic -> show leds`.
 
 ```sig
-basic.plotLeds(`
+basic.showLeds(`
 . . . . .
 . # . # .
 . . # . .
-# ; . . #
+# . . . #
 . # # # .
 `)
 ```
@@ -16,14 +16,14 @@ basic.plotLeds(`
 
 * leds - a series of LED on/off states that form an image (see steps below)
 
-### Example: simley
+### Example: smiley
 
 ```blocks
-basic.plotLeds(`
+basic.showLeds(`
 . . . . .
 . # . # .
 . . # . .
-# ; . . #
+# . . . #
 . # # # .
 `)
 ```
diff --git a/docs/reference/types/number.md b/docs/reference/types/number.md
index 8d7cde64..ecddb249 100644
--- a/docs/reference/types/number.md
+++ b/docs/reference/types/number.md
@@ -61,7 +61,7 @@ The [math library](/blocks/math) includes math related functions.
 For example, the `absolute` function returns the returns the absolute value of input parameter `x`:
 
 ```blocks
-let abs = math.absolute(-42);
+let abs = Math.abs(-42);
 basic.showNumber(abs);
 ```