Numbers to 20, adding and subtracting

See 11 to 19 as one ten and some ones, like a carton of eggs, and learn to say each number.

Count 11 to 20 with ten frames, groups of ten and coins. Make a ten, then count on.

Two tens make 20. Match the same number shown as fingers, rods, tally marks and words.

Draw more, circle, pick coins and keep just enough: move freely between a number and an amount.

Put 1 to 20 in order, find missing and next numbers, and place numbers on a number line.

Count back from 20 to 1, find the number just before, and spot mistakes in a backwards row.

Say first to twentieth, and see how the place changes when you count from the left or the right.

Find one more, one less, and the number in between.

Count, write and compare two numbers, and say it in a sentence: "20 is bigger than 15."

Find the biggest and smallest of three or four numbers, even when they are written in different ways.

Find numbers that fit a rule, like "greater than 13" or "between 10 and 17".

Arrange several numbers from smallest to biggest and from biggest to smallest.

To join two groups, start at one number and count on: from 10, or from 8.

Split 11 to 19 into two parts, in more than one way.

Join two numbers like domino dots to make 11 to 19.

Switch between joining and splitting to see how two parts and a whole belong together.

Write a number as the sum of two numbers, like 16 = 10 + 6.

10 + 2 = 12. Ten plus some ones makes a teen number.

If you know 3 + 4 = 7, you know 13 + 4 = 17. Add the ones, then add the ten.

Practise teen plus a digit with pictures, equations, blanks and word problems.

Adding zero changes nothing: 12 + 0 = 12 and 0 + 15 = 15.

5 + 12 and 12 + 5 have the same sum. Swapping the numbers does not change the answer.

Finish addition with true-or-false, the biggest sum and equal sums.

12 − 2 = 10. Take away all the ones and ten is left.

If you know 6 − 4 = 2, you know 16 − 4 = 12. Subtract the ones and keep the ten.

Practise teen minus a digit with pictures, ten frames, blanks, comparing and word problems.

Subtracting zero changes nothing; subtracting the same number leaves zero.

Finish subtraction with true-or-false, the biggest difference and equal differences.

Choose the equation that matches a picture and see how adding and subtracting connect.

Chain calculations, compare answers and solve stories to finish Stage 1.