# 6.3. Keep & Combine¶

The other two blocks we will use that take other blocks as input are Keep* and **Combine. This video introduces them:

### Checkpoint Exercises

All of the checkpoint exercises will work on the lists shown to the right. Start by making lists that look like them.

Hint:

The combine with block should have two blanks in the reporter you use for “smashing things together”. Like this:

If you put something in one of the blanks it won’t work right!

### Keep Exercises

Keep less than 80

Use Keep to filter the list of numbers down to those less than 80.

Keep long words

Use Keep to filter the list of words down to only words with a length of more than 4.

You need to use the block.

### Combine Exercises

Multiply

Use Combine to multiply all the numbers in the numbers list together.

Select Minimum

Make a reporter block that returns the smaller of two values. Use Combine and that block to combine the list of numbers - you should get 68. Use them to combine the words, you should get “i” (the lowest alphabetically).

Select Longest

Make a reporter block that returns the longer of two words. Use Combine and that block to combine the list of words - you should get “programming”, the longest word