I was trying to find a way to teach numbers without teaching the numbers monotonously. What I did was to make a bunch of cards where a simple equation is written but the maths is really really easy.

1+2=
4x2=
7-6=
6dividedby3= (where is the divided by sign on a PC keyboard, don't use slash for kids)

etc

Make up a bunch of these using the 4 maths symbols and all the answers are 0-15.
It gives the kids a chance to pick up those pesky "threeteen and fiveteen" numbers and the odd eleven and twelve which they stumble.

Make half the cards using one colour blue , and another using red.

1) Round 1 - say answer in English
2) Round 2 - say in Japanese
3) Round 3 when the card is blue, say in English, if red say in Japanese.

This game works well with two or three teams, kuruta style, and best for 5-6 graders especially when they either get the English or Japanese wrong , or they simply cannot do simple sums. The students laugh at each other especially when it comes to their turn and they get it totally wrong too. It's always easier to watch others until it is your turn.
I also tried the game with 4 graders who were a bit slow with some kids getting tired whilst others were really active.

But you'll be surprised how, by the end of the lesson, the kids pick up many of the higher numbers without having a thought of Japanese or English. Some kids actually do it better in English !!

Variation -
4) Round 4 for upper elementary levels - I give the actual answer in English or Japanese whilst at the same time showing the card to the students, and the first student to reply must either say (if I gave the answer in English) "Yes it is/No it is not", or (if I gae the answer in Japanese) "sou desu/ja nai".

As a booby prize, I gave the team with the fewest cards a copy of (old) Grade 1's maths text book for laughs.

I think in Japan, kids do addition/subtraction by Grade 1, Multiplication by Grade 2, Division by Grade 3. The level may vary a bit so keep this game for upper level elementary kids.

cool ideas there!

It reminds me of a simple activity I thought up the other day, it can be played as a game or a round

Just count from 0 to 100 using a dice, throw the dice and the 1st team to say the correct next number gets the point.

Another idea is to go around the class in turns with odd numbers being said in English and even in Japanese and then change (that gets them thinking)

hi there, am always very against translating or speaking in another language that is not the target language. i recently taught the numbers and i use a song counting by 10's. This was very productive for my ss they range from 7 to 15.

I got it from my children's

counting by 10's its so much fun
counting by 10's it can be done
if we practice over and over again
we will learn how to count by 10's

10-20-30-40-50-60-70-80-90-100 that's it
and to add some motivation, change the speed the love the faster they go. also am using the speakopology with the numbers that give them problems.

almost forgot how much fun the kids having playing uno...its great they practice the numbers and colors....and when teaching from 10 to 100 just make them add a 0 after the numbers so 1=10 and so forth....they really loved this game