Adding a single digit to a 3-digit number; there might well be plenty of counting on fingers here!

Without using paper and pencil practise adding three small numbers as well as adding two 2-digit numbers.

Once the technique for adding 9 to a number has been mastered, there is no problem with adding 19, 29 or 39!

Work carefully, using patterns such as pairs of numbers that make 10, to help answer these.