Search Results For “problems x10 and 100”

Adding 9 or 11 to 3-digit numbers by adding 10 and adjusting.

More practice at adding the nearest whole ten and adjusting, as well as looking at addition patterns.

Adding several numbers. A useful tip is to look for pairs of numbers that make 10 and do that part of the sum first.

Several ways to investigate the relationship between addition and subtraction.

More adding multiples of 10 to 2-digit and 3-digit numbers. The units remain the same in these questions.

Taking 15, 16, 17 or 18 from 2-digit numbers. The easiest way of doing this is by taking a whole ten and adjusting.

Finding the difference between two numbers as well as making subtraction number sentences from the numbers given.

Remember that subtractions can also be done by subtracting the nearest whole ten and adjusting.

A mixed selection of adding and subtracting multiples of 10.

Subtraction by compensation means taking away more than you need and then adding some back. It can be quite an effective way to subtract.

Subtraction by decomposition is the way most adults are familiar with and is the way that children will ultimately use for larger numbers. Here is an introductory exploration of the idea.

Progressively harder doubling and halving; from teens, to 2-digit multiples of 5 to 3-digit multiples of 10.